Category Archives: vitamin a

foods high in vitamin a

Many plant-based eaters are under the impression that they can obtain all the vitamin A that they need from plant foods that contain carotenoids, particularly beta carotene found in foods like spinach, sweet potatoes, and carrots.

It’s true that some carotenoids like beta carotene can be converted to vitamin A in your body once they make it into your blood. What you may not know is that carotenoids are not always absorbed efficiently into your blood.

Given that vitamin A deficiency is one of the most common nutritional deficiencies in the world and is also a leading cause of death in young children, it’s critical for the general public to know that relying solely on carotenoids in plant foods for daily vitamin A needs may lead to any of the following health problems over time:

Skin Lesions Like Acne and Acne Rosacea: Vitamin A is needed to develop and maintain moist and healthy epithelial tissues, including your skin. Many long time vegans find it difficult to understand why they have acne while on a whole food, plant-based diet. Vitamin A deficiency is undoubtedly a common cause of acne for all acne sufferers, but particularly for people who eat mainly a plant-based diet and don’t include a reliable source of vitamin A in their diets.

Poor Night Vision: Vitamin A combines with a protein in the back of your eye to enable night vision.

Weak Bones, Weak Teeth, and Poorly Spaced Teeth: Vitamin A is needed for proper growth and maintenance of bones and other soft tissues throughout your body.

A Weak Immune System: Because vitamin A is needed for the development and maintainance of all of your body’s barriers to infection like your skin, lungs, and the mucosal linings in your digestive and urinary tracts, a deficiency almost assures you of an immune system that is not as strong as it can be.

Cancer: Since vitamin A is essential to the health of your immune system, a deficiency could increase your risk for developing certain forms of cancer, such as breast, lung, stomach, and cervical cancer.

Anemia and Associated Fatigue: Vitamin A is needed for proper red blood cell formation.

Vitamin A is actually a group of compounds that includes retinol, retinal, and the carotenoids. Retinol and retinal are found in animal foods such as liver, eggs, and butter. Because these forms of vitamin A are ready to be used by your body straight from their food sources, they are often referred to as pre-formed vitamin A.

Carotenoids, in turn, are often referred to as provitamin A since they are precursors to Vitamin A and need to be converted in your body.

The total vitamin A in your diet is therefore a combination of the pre-formed vitamin A and provitamin A in your diet.

It’s important to note that optimal absorption of retinol, retinal, and the carotenoids into your blood requires an adequate amount of healthy fat in your diet. This is because pre-formed and provitamin A are fat soluble compounds that are best absorbed into your blood in the presence of digestive juices that are needed to digest fat. The more healthy fat you include in your diet, the better you will absorb fat soluble vitamins A, D, E, and K into your blood.

I don’t believe it’s practical to offer a chart that lists specific amounts of useable vitamin A in different foods because the amount of vitamin A that ultimately reaches your blood depends on the variables described above.

So, here are two simple lists of healthy foods that contain significant amounts of pre-formed and provitamin A. I believe that it is best for most people to eat foods from both groups on a regular basis to to meet their daily vitamin A needs.

Pre-formed Vitamin A:

  • Organic beef liver
  • Organic lamb liver
  • Organic eggs
  • Organic butter
  • Cod liver oil

Provitamin A:

  • Sweet potatoes or yams
  • Canteloupe
  • Spinach
  • Carrots
  • Butter nut squash

What About Toxicity?

With the exception of cod liver oil, all of the other foods listed above have virtually no potential to cause vitamin A toxicity in your tissues. So long as you stick to an appropriate dose of cod liver oil, you can rest assured knowing that you aren’t getting too much vitamin A each day.

Every study that I have looked at that discusses the potential for vitamin A toxicity looked at synthetic sources of vitamin A. Clearly, it is best to get vitamin A from the healthy foods listed above and to avoid synthetic sources at all times.

Foods that Contain Vitamin A

Both animal and plant foods have vitamin A activity. Retinol, also called preformed vitamin A, is the natural form found in animals. Carotenoids, found in plants, are compounds that the body can convert to vitamin A.

Liver is the single best food source of vitamin A. However, many experts recommend eating liver only once or twice a month because of the toxic substances it can contain. Environmental pollutants tend to congregate in an animal’s liver. Egg yolk, cheese, whole milk, butter, fortified skim milk, and margarine are also good sources of vitamin A. Be careful, though, as all these foods — except fortified skim milk — are also high in total fat and saturated fat, and all except margarine are high in cholesterol. Red palm oil, used for cooking in many tropical countries, and fish liver oils taken as supplements are also rich in vitamin A. One tablespoon of cod liver oil contains more than 12,000 international units (IU), more than twice the daily recommended intake for adults.

Because of the high fat and cholesterol content of most vitamin A-rich foods, as well as the potential for overdosing, it is recommended that you do not overeat from these sources just to fulfill your need for vitamin A. (Recent studies suggest that vitamin A, as retinol, can be toxic at much lower doses than previously thought.) Currently, Americans get about half their vitamin A as retinol from animal sources and half as carotenoids from plant sources.

This chart will help you find foods that are a good source of vitamin A.

Food Quantity Vitamin A Content International Units (IU) Retinol Equivalents (RE)
Baked sweet potatoes, peeled 1 medium 28,805 2,881
Pumpkin, canned 1/2 cup 27,018 2,702
Sweet potatoes, candied 1 medium 25,188 2,519
Beef liver, cooked 2 ounces 20,230 6,130
Spinach, canned, drained 1 cup 18,781 1,878
Sweet potatoes, canned 1 cup 15,966 1,597
Spinach, cooked, fresh or frozen 1 cup 14,790 1,479
Carrot, raw 1 medium 12,767 1,277
Cantaloupe 1/2 medium 12,688 1,269
Peas and carrots, frozen (boiled, drained) 1 cup 12,418 1,242

vitamin A foods

What might high-vitamin A foods complete available for you?

  • Preserve as well as improve your sight
  • Help people control infections

What celebrations can often mean a necessity for much more high-vitamin A foods?

  • Frequent viral infections
  • Night blindness
  • Goose bump-like appearance of your skin layer

Although vitamin A is found merely in foods of puppy basis, a lot of fiber rich foods contain substances, generally known as cartenoids, that may be converted into vitamin A through your figure. Food sources of preformed vitamin A include lower leg ailing liver, milk products, along with eggs.

What is definitely vitamin A?

Vitamin A, acknowledged found in 1913, is the primary fat-soluble vitamin to become found. A gentle yellowish crystalline chemical substance, vitamin A is in addition identified as retinol, a title succumbed experience with that taking part of this supplement during the options of the actual retina of the interest rate. Vitamin A has been referred to as the “anti-infective” vitamin because part within keeping those actions of a immune system.

While retinol, and / or preformed vitamin A, shows up sole on foods of canine origins, fruits and vegetables that may contain positive carotenoids have vitamin A recreation. Carotenoids can be grow colors, chargeable for the particular inflammed, lemon, plus stained colors of fiber rich foods.

The shape could transfer a number of customers of the carotenoid families, including beta-carotene, alpha-carotene, as well as gamma-carotene, towards vitamin A. Such carotenoids will often be referred to as “provitamin A,Inches plus retinol since “preformed vitamin A.”

Vitamin A (or even Vitamin A Retinol, retinal, and then a number of carotenoids among them beta carotene) can be a vitamin that is needed with the retina of the attention while in the manner of a particular metabolite, all the light-absorbing molecule retinal, that would be absolutely necessary for both equally low-light (scotopic imaginative and prescient vision) and also color choice ideas. Vitamin A too attributes on a unique function, if you are an irreversibly oxidized sort of retinol referred to as retinoic acid, which happens to be a critical hormone-like improvement thing pertaining to epithelial together with other cellular material.

In foods of pet animal beginning, difficulties variety of vitamin A is definitely an ester, mostly retinyl palmitate, that is certainly converted to that retinol (chemically a liquor) on the modest intestine. All of the retinol manner functions mainly because a storage area manner of typically the vitamin, and will get converted to as well as by reviewing the visually working aldehyde type, retinal. This connected acid (retinoic acid), a metabolite which could be irreversibly synthesized from vitamin A, has only partial vitamin A hobby, as well as doesn’t characteristic while in the retina with the video or graphic bike.

All forms of vitamin A now have a beta-ionone diamond ring to which a good isoprenoid stringed might be hooked up, called a retinyl group. Each of those basique benefits essential just for vitamin exercise.[1] Your fruit coloring of pumpkin ¡§C beta-carotene ¡§C is often displayed mainly because not one but two related retinyl sets, that will be utilised in our bodies to make sure you create vitamin A levels. Alpha-carotene together with gamma-carotene also have a solo retinyl staff, which in turn give them certain vitamin physical activity. It’s unlikely that any of the opposite carotenes now have vitamin exercise. All the carotenoid beta-cryptoxanthin contains the ionone staff and possesses vitamin actions on humankind.

Vitamin A come in only two crucial varieties for foods:

Retinol, the shape of vitamin A taken in in the event that feeding on critter food sources, is definitely a green, fat-soluble material. Considering that the real beer form is risky, the actual vitamin is found flesh throughout a sort of retinyl ester. It could be in a commercial sense released not to mention governed because esters which include retinyl acetate and / or palmitate.

The carotenes alpha-carotene, beta-carotene, gamma-carotene; as well as xanthophyll beta-cryptoxanthin (many of that contain beta-ionone wedding bands), nevertheless few other carotenoids, really do the vitamin A within herbivores along with omnivore critters, which will enjoy the chemical needed to enhance a lot of these molecules towards retinal. Typically, carnivores are generally bad converters of ionine-containing carotenoids, together with organic carnivores such as kittens and cats and also ferrets loss beta-carotene 16,15′-monooxygenase and should not convert virtually any carotenoids to retinal (bringing about no one of all the carotenoids appearing kinds of vitamin A because of these types of fish).

Substance and it is compound environment Micrograms of retinol equivalent
per microgram of all the substance
retinol 1
beta-carotene, dissolved for oil 1/2
beta-carotene, standard dietary 1/12
alpha-carotene, standard dietary 1/24
gamma-carotene, prevalent dietary 1/24
beta-cryptoxanthin, frequent dietary 1/24

Because the particular the conversion process of retinol through provitamin carotenoids by way of the human is actually regular via the amount of money of retinol there for the body, all the conversion rates make an application stringently exclusively for vitamin A-deficient individuals. Any assimilation of provitamins would depend tremendously relating to the volume of lipids swallowed along with the provitamin; lipids expand the usage of typically the provitamin.

The bottom line that might be utilized by the more modern research is the fact that fruits and additionally veges don’t seem to be as useful for acquiring vitamin A since was basically considered; in other words, all the IUs the foods ended up announced so that you can contain were value a lot less than the very same figure of IUs of fat-dissolved motor oils and even (rather) pills. This will be significant for veges, since Afternoon blindness is undoubtedly rampant on countries around the world when minimal the meat selections or even vitamin A-fortified foods can be obtained.

A sample vegetarian diet personally evening which gives satisfactory vitamin A may be publicized through the Food not to mention Eating habits Panel (article 130). Having said that, benchmark ideals for retinol and it is counterparts, furnished by the National Academia of Sciences, now have diminished. All of the RDA (males) of 68 was first 5,000 IU (2500Throughout The 1974 season, all of the RDA was in fact fixed so that you can Million Re also (Thousandhowever the Health Reference point Absorption is normally 900 RAE (Nine hundredand even 3300 IU retinol). It is likesupplement (3,000 IU) and / orduring food (18000 IU).

Vitamin A deficiency and Symptoms

Basically, Vitamin A is a classification of organic compounds that has significant role for healthy vision, strong bones, supple skin, normal cell regeneration and reproduction. Vitamin A also helps the immune system to ward off infections.

Vitamin A types found in foods especially from animal products are called retinol or pre-existing Vitamin A. it is the most functional form of Vitamin A. retinol can easily convert it to retinoic acid for your metabolism. Rich sources of retinol are milk products, eggs, liver and fortified and supplementary food.

Vitamin A deficiency is very common in developing nation but is very rare in developed nations. Nyctalopia or night blindness is a common symptom of Vitamin A deficiency. Other eye diseases such as Xeropthalmia and total blindness are also possible since Vitamin A has a significant role in the conversion of the electrical signal in the rod cells in retina of your eyes.

About 500,000 under nourished children in the developing nations goes blind every year because of deficiency in Vitamin A, wherein about half of this number die within a year of being blind.

The incidence of nyctalopia as a cause of vitamin A deficiency is on the rise among pregnant and lactating mothers from developing nations. Vitamin A deficiency also increase occurrence of maternal death and other health risks among women.

Vitamin A deficiency also decreases the ability of the human body to fight infections. In nations where children did not received immunizations, contagious diseases such as measles have been noted for their higher mortality rates.

The kinds of vitamin A extracted from plant and plant products are known as provitamin A carotenoids. A good example of carotenoids is beta-carotene. The human body can convert these carotenoids into antioxidants necessary to guard your body against any invading virus. Rich sources of carotenoids are fruits with bright colors, dark green vegetables such as carrots, spinach fruits such as papaya and mango.

Vitamin A deficiency as a result of insufficiency of healthy snacks is rare in developed nations and is more likely as a consequence to swollen infections that damage the digestive system and avoid absorption of Vitamin A, such as Celiac disease. Excessive intake of alcohol, zinc deficiency and diseases of the pancreas can also influence the levels of vitamin A in your body and avoid symptoms.

If you have vitamin A deficiency symptoms, you need to consult your physician who can instruct for medical exams such as blood tests to settle on if a Vitamin A deficiency is the cause or if there are other symptoms.

If you think you are deficient in Vitamin A, or if you are young yet you experience symptoms such as difficulty in your vision, this is one of the Vitamin A deficiency symptoms.

There are critical cases of Vitamin A deficiency on many children. In these cases, specific eye problems and symptoms could happen due to failure of the optical nerves that could risk your child’s vision forever. These cases ar every rare in developed countries. However, it is better to give your family healthy snacks and meals that are rich in vitamin A.

Here we will discuss vitamin A deficiency symptoms. Vitamin A participates in many important processes which take place in human body, so if it comes to vitamin A deficiency it will result in problems, sometimes very serious conditions. In children this can lead to problems with growth and bone quality as well as respiratory disorders. This description of symptoms will help you recognize whether you lack vitamin A.

You may lack vitamin A if you are having problems to see in dim light (or at night) or if having problems to adapt your vision to darkness. We already know that one of the roles vitamin A has in human organism is to maintain the vision. Other symptoms are also related to eyes conditions: dry eyes and tiny light colored (nearly white) spots in the eyelids. If one doesn’t react in time, severe complications regarding vision can occur – as severe as blindness, so do not ignore these symptoms. Further on, if you are experiencing trouble in sensing tastes, this is one more indicator that you may lack vitamin A.

Deficiency of vitamin A also reflects through your skin condition. If your skin is dry or your wounds won’t heal, vitamin A deficiency is to blame. If your hair and nails are dry and weak, your body is obviously telling you that you need more of vitamin A.

The main cause to vitamin A deficiency is a bad diet. If having any doubts, blood test will show if there is something to treat. But even if you are fine and with no similar symptoms, you should keep in mind the importance of well balanced diet and should be informed about foods with vitamin A. That way you can prevent your body to suffer from vitamin A deficiency by using simple and natural means such are foods. Also, these problems are common in old people.

Vitamin A Benefits

Vitamin A, also called retinol, helps your eyes adjust to light changes when you come in from outside and also helps keep your eyes, skin and mucous membranes moist. Vitamin A mostly comes from animal foods, but some plant-based foods supply beta-carotene, which your body then converts into Vitamin A. It also has antioxidant properties that neutralize free radicals in the body that cause tissue and cellular damage.

Early information from scientific studies suggests that beta-carotene might help people who already have Coronary Artery Disease (CAD). The American Heart Association doesn’t recommend taking supplements of beta-carotene until more is known, however.

Nutritionists categorize vitamins by the materials that a vitamin will dissolve in. There are two categories: water-soluble and fat-soluble vitamins. Fat-soluble vitamins A, D, E and K are stored in the fat tissues of the body for a few days to up to six months. If you get too much of a fat-soluble vitamin, it can be stored in your liver and may sometimes cause health problems. Vitamin A is a fat-soluble vitamin.

Some people take mega-doses of fat-soluble vitamins, which can lead to toxicity. Eating a normal diet of foods rich in these vitamins won’t cause a problem. Remember, you only need small amounts of any vitamin. In the case of vitamin A, overconsumption has been linked with an increased risk of fractures in postmenopausal women.

Some health problems can make it hard for a person’s body to absorb these vitamins. If you have a chronic health condition, ask your doctor about whether your vitamin absorption will be affected.

How Much Vitamin A Is Enough?
It’s recommended that women consume 800 mcg and men consume 1000 mcg of vitamin A daily.

Sources of Vitamin A

Top sources of vitamin A include:

  • Beef liver
  • Egg yolk
  • Cheddar cheese
  • Fortified milk

Top sources of beta-carotene include:

  • Sweet potato
  • Carrots
  • Pumpkin
  • Cantaloupe
  • Broccoli
  • Apricots
  • Spinach and collard greens

Can You Have Too Much or Too Little?
Vitamin A deficiency is rare in the United States, but it can cause night blindness, eye inflammation, diarrhea and other problems. Overconsumption of vitamin A can cause nausea, irritability and blurred vision in its mild form. In addition, the palms of the hands and the bottoms of the feet can turn orange if a person has a high intake of Vitamin A. Vitamin A toxicity can cause growth retardation, hair loss and enlarged spleen and liver in its more severe form. Vitamin A overdose can also cause birth defects and has been linked to increased risk of bone fractures in some people.

Vitamin Storage
If you want to get the most vitamins possible from your food, refrigerate fresh produce, and keep milk and grains away from strong light. Vitamins are easily destroyed and washed out during food preparation and storage. If you take vitamin supplements, store them at room temperature in a dry place that’s free of moisture.

Good sources of Vitamin A

We said above that we most often see vitamin A as bright orange. This is true to a large extent in plant sources, which are in the form of beta carotene. For instance, some of the very best sources of beta carotene are carrots, sweet potatoes, pumpkin, winter squash, mangoes, papayas, peaches and cantaloupe. But there are other sources, some of which are dark green like beet greens, broccoli, Swiss chard and spinach.

Most milk products and egg yolks also have significant quantities of “preformed” vitamin A (retinol), as do some fish. Perhaps the most concentrated source of retinol vitamin A is liver � calves live, chicken liver, pork liver, any liver.

Get the Most From Your Vitamin A

Refrigerate fruits and vegetables in sealed containers and eat them raw whenever possible. Vitamin A is stored in the liver (which is why eating liver is a good source of vitamin A). Like all fat soluble vitamins, it does not get flushed out daily. However, it is recommended to get a good quantity of vitamin A on a daily basis. The stored vitamin A will provide your body with its needs when you have a lower intake of beta carotene or retinol.

Vitamin A Deficiency

In a Venezuelan study, Jimenez et al investigated the effect of a single, oral 200,000 IU dose of vitamin A on iron and vitamin A nutritional status, the phagocytic function of neutrophils, and the rate of anemia, in a population of preschool children with a high prevalence of VAD. The study group consisted of 80 children, including 12 controls; no iron supplementation was provided.

In an assessment of the children 30 days after the administration of vitamin A, the authors found that those who had received the supplement exhibited a significant increase in concentrations of hemoglobin (Hb), mean corpuscular Hb, and serum retinol, while the rates of anemia and VAD among the children fell from 17.6% to 13.2% and from 25% to 13.2%, respectively. In addition, the phagocytic capacity of neutrophils increased in the supplement group. The authors concluded that vitamin A supplementation could help to decrease the frequency of VAD and anemia, as well as to increase the immune response, in preschool children.

Hypovitaminosis A Vitamin A deficiency is a very common problem in pet birds. When caught in its early stages, it is easily reversible with little harm done. If it is not corrected, it can have serious consequences. Hypovitaminosis A is often seen in birds that are on an all seed or mostly seed diet. Not only is an all seed diet low in Vitamin A, but also does not provide the bird with other needed minerals and vitamins as well.

With the advent of pelleted or formulated diets, a more balanced diet is obtainable for pet birds. These diets general have an adequate amount of Vitamin A when they leave the manufacturing plant. However time and temperature are enemies of Vitamin A. There can be quite a bit of time from the day it was manufactured to the time you take it home and finally feed it to your bird. There is the amount of time tied up in shipping, warehousing, redistribution, and then storage again.

Anything that causes a gut upset in the bird can interfere with digestion of carotenoids. Giardia and Cocida (Psittacosis) are two notorious problems that contribute to Hypovitaminosis A. If the liver is not functioning properly due to infection, a toxin, or being overweight, it won’t be able to make the conversion to Vitamin A.

Plants do not contain active Vitamin A, but instead contain carotenoid plant pigments. Once a Vitamin A food source is eaten, the crop and proventriculus process it before passing it into the intestines. Once inside the intestines, the carotenoid pigments are absorbed through the intestinal wall and converted to retinol, or Vitamin A. Retinol is then transported by the lymph system and the blood to the liver. If there is any extra retinol, it is stored in the fat held by the liver.

Birds with a protein-deficient diet will not digest and absorb Vitamin A properly. Protein is necessary for a healthy intestinal wall. This protein is important since the intestinal lining has rapid cell replacement. These cells are fundamentally protein.

It takes more than lust feeding birds food known for their carotenes. To be able to use these carotenes and convert them to Vitamin A, a bird must have the other nutrients needed for this conversion. The sinuses become more vulnerable to bacterial infections when a bird suffers from a Vitamin A deficiency. Sneezing, wheezing, nasal discharge and crusted or plugged nostrils are not only an early symptom of this, but can be symptoms for many other health problems as well.

Vitamin A is essential for vision. One of the earliest signs of this deficiency is night blindness. This is caused by a degeneration of the rods of the retina. The eyes may become swollen and weepy. Inflammation and abscess material may accumulate around the eye. Sometimes it is necessary to surgically remove the abscess material. The tear glands can be affected as well.

Vitamin A is known for its role in protecting the body against infections. There are little hair-like structures that help to keep the mucous flowing around cells. When there is a Vitamin A deficiency, these structures dry up and infections can occur because the cells are not bathed or cleansed. A bird may become thin due to lack of eating. He may play with his food rather than eat it. Sometimes a bird will experience gagging. His breath may become foul smelling and his breath slimy. If you open his mouth you will notice white patches. Although these are caused by a yeast-like organism, Candida albicans, the trigger is more than likely a deficiency of Vitamin A. These slimy cheesy yellow or white patches of Candida growth can also appear in the throat. This plaque becomes infected, forming an abscess. These abscesses can lead to nasal discharge and swollen eyes. When very severe, these abscesses can lead to suffocation.

The choana (slit in the roof of the mouth may be swollen, and the papillae may be fewer or completely absent. When the salivary gland is affected, there is a swelling under the jaw. This has been noted in Amazons, African greys and Cockatoos. 50% of the Amazon parrots examined during necropsy at the veterinary school at The University of California Davis showed evidence of a Vitamin A deficiency in their salivary glands.

A bird may increase the amount of water that he would normally drink. This leads to increased urination. If damaged cells block the tubes that drain urine, the kidneys can start to fail. When the waste backs up, it will cause toxicity.

Bones need Vitamin A to develop properly. Without a sufficient amount they become weak or bent.

Feet can show that the bird is suffering from a Vitamin A deficiency. The scales may appear thickened and be abnormally shaped. The undersides of the foot appear smooth and warn. Corns appear on the pads. This may lead to a serious foot infection called bumble foot. Bumble foot is caused by a bacterial infection on the underside of the toes and on the ball of the foot. The infection can spread from the foot and travel through the blood to the kidneys. This can damage the kidneys as well as other organs. This infection is easier to prevent than cure, so it is better to catch it before it gets out of hand.

Another area affected is that of reproduction. The eggs produced by the hen can show many signs. Eggs may have pitted or very soft shells. Blood vessels grow improperly in embryos. The chicks either die in the shell or are very weak at hatching. There can be a decrease in egg production and in the hatch-ability. There are increased blood spots in the eggs of unsuccessful clutches. Fertility in males may be impaired because of decreased sperm counts. There can be high levels of abnormal sperm, or sperm with decreased ability to swim and move properly.

When you bring your bird to your veterinarian for a Vitamin A deficiency, the vet will give the bird a thorough physical exam. Then through blood tests, cytology of lesions, and gram stains she will decide how the bird should be treated. If there is a secondary infection, that will be treated. She may initially give an injection of Vitamin A and give you a diet for your bird to prevent it from coming back.

Since Vitamin A symptoms have some of the same as avian tuberculosis, bacterial infections, tumors, etc., it is best to have a person that can determine he true cause of the bird’s problem. It is unwise to self diagnose your bird. You may treat the bird as having a Vitamin A deficiency when it could be something else.

The word vitamin was originally derived from Funk’s term “vital amine.” In 1912, he was referring to Christian Eijkman’s discovery of an amine extracted from rice polishings that could prevent beriberi. Funk’s recognition of the antiberiberi factor as vital for life was indeed accurate. Researchers have since found that vitamins are essential organic compounds that the human body cannot synthesize. Vitamins A, D, K, and E are classified as fat-soluble vitamins, whereas others are classified as water-soluble vitamins.

Vitamin A was the first fat-soluble vitamin to be discovered. Early observations by ancient Egyptians recognized that night blindness could be treated with consumption of liver. Two independent research teams, Osborne and Mendel at Yale University and McCollum and Davis at the University of Wisconsin, simultaneously discovered vitamin A in 1913. Vitamin A is made up of a family of compounds called the retinoids. The retinoid designation resulted from finding that vitamin A had the biologic activity of retinol, which was originally isolated from the retina.

There are essentially 3 forms of vitamin A: retinols, beta carotenes, and carotenoids. Retinol, also known as preformed vitamin A, is the most active form and is mostly found in animal sources of food. Beta carotene, also known as provitamin A, is the plant source of retinol from which mammals make two-thirds of their vitamin A. Carotenoids, the largest group of the 3, contain multiple conjugated double bonds and exist in a free alcohol or in a fatty acyl-ester form.

In the human body, retinol is the predominant form, and 11-cis -retinol is the active form. Retinol-binding protein (RBP) binds vitamin A and regulates its absorption and metabolism. Vitamin A is essential for vision (especially dark adaptation), immune response, bone growth, reproduction, the maintenance of the surface linings of the eyes, epithelial cell growth and repair, and the epithelial integrity of the respiratory, urinary, and intestinal tracts. Vitamin A is also important for embryonic development and the regulation of adult genes. It functions as an activator of gene expression by retinoid alpha-receptor transcription factor and ligand-dependent transcription factor.

Deficiency of vitamin A is found among malnourished, elderly, and chronically sick populations in the United States, but it is more prevalent in developing countries. Abnormal visual adaptation to darkness, dry skin, dry hair, broken fingernails, and decreased resistance to infections are among the first signs of vitamin A deficiency (VAD).

Feather color and condition are dependent on the bird’s diet. Vitamin A is needed for the formation of the orange and red pigment in the feathers. Black, chewed feathers often point to a diet low in Vitamin A. Spirulina is often fed birds to maintain proper feather coloration.

Always consult your vet before supplementing your bird with Vitamin A. It is a fat-soluble vitamin and is toxic when too much has been given. A bird’s body stores the Vitamin A so you can easily overdose. Foods with beta-carotenes will not cause an overdose of Vitamin A as they are not convened into Vitamin A until it is needed. Feeding foods known for the high amount of carotene may not be the answer even though you will not overdose the bird through food. Unless other nutrients are also in his diet, he will not be able to convert the carotene to Vitamin A.

High amounts of Vitamin A can result in temporary yellow or orange coloration’s of the skin and fat. Tetracycline treatment has been shown in some animals to produce toxicity at lower does of Vitamin A. A compromised liver can also lead to Vitamin A toxicity at low levels. You must be very careful when giving Vitamin A supplements to birds on a pelleted diet, as most of them already contain the required amount. Adding Vitamin A supplements to them can overdose the bird. The practice of adding cod liver oil is equally risky. It can easily become rancid, so must be stored properly. The Vitamins A and D found in cod liver oil are both fat soluble and there fore can be stored in the body This increase the chances of giving the bird too much.

Birds generally die from secondary infections caused by the weakened resistance from he Vitamin A deficiency more than from the deficiency itself. The secondary infections cause the organ damage that leads to the bird’s eventual death.

7 Health Benefits of Vitamin A

Vitamin A, also known as retinol, is a fat-soluble vitamin that occurs only in animal foods. Carotenoids, however, serve as a great source of alpha-, beta-, and gamma-carotene that our bodies convert into vitamin A and can be found in many vegetables and fruits.

It is indispensable for our health and is especially abundant in foods such as apricots, broccoli, cantaloupe, carrots, kale, liver, mangos, red peppers, spinach and sweet potatoes. Here are seven reasons why you should make sure that your diet includes vitamin A.

Immunity
Not only does Vitamin A strengthen “entry points” into the human body, such as mucous membranes, the lining of the eyes, respiratory, urinary and intestinal tracts, it is also essential for the lymphocytes, or white blood cells, that fight infection once in the body.

Eyes
Vitamin A, when converted into the retinal (retinaldehyde) form, is vital for healthy eyes. It allows the eye to effectively distinguish between light and dark, thus improving night vision. Furthermore, vitamin A is believed to fight against cataracts, macular degeneration, glaucoma and other age-related ocular diseases.

Bones and Teeth
When converted into retinoic acid, vitamin A effectively maintains healthy bones and teeth. Dentin, which also requires vitamin A, forms the hard layer of material within our teeth, thereby ensuring their strength. Vitamin A also plays an important role in replacing worn out or old tissue with newer tissue to ensure healthy bones and teeth.

Urinary Stones
Urinary calculi, or solid particles in the urinary system, may cause pain, nausea and vomiting when stones are formed. Vitamin A produces a mineral compound within the body called calcium phosphate that prevents the formation of these solid particles.

Cancer
As a powerful antioxidant, vitamin A fights against oxidative stress, or “cellular rust,” within our bodies, thus protecting us from health problems such as cataracts, atherosclerosis, chronic obstructive pulmonary disease, and cancer.

Skin
The antioxidant properties of vitamin A combat free radicals that can damage the skin through oxidative stress. By maintaining proper moisture retention, the skin is not only protected from common dryness, but also keratinization (the process in which the epidermis hardens into a heavy material that makes up hair and nails), psoriasis (a skin disease marked by red, itchy or scaly patches), acne, and even wrinkling.

Reproductive System
Vitamin A is known to be essential for the reproductive process for both males and females.

Best absorbed together with little oil or fat in our diet, a person thinking of taking vitamin A supplement should stay with the “natural fish oil ” forms.

The best source of vitamin A is of course the one provided by nature since unlike the supplement form, nature’s source of vitamin A can never be toxic.

Vitamin A in Nature :

In nature vitamin A comes in two forms. One is retinol: something that you’ll find in liver, dairy products, eggs or cod liver oils.

The second form of nature’s vitamin A is beta-carotene, an orange-yellow to red pigment that the body converts to vitamin A when necessary. Beta-carotene is found in brightly colored fruit and vegetables. The brighter the fruit, the more beta-carotene it contains.

You will find beta-carotene in vegetables and fruits like apricots, broccoli, tomatoes, carrots, spinach etc. For your information, taking large amount of vitamin A supplements for a long time can be bad for your health, but you don’t get the same side effect by taking a large amount of fruits or vegetable that contains beta-carotene. This substance has also been found to prevent cancer by neutralizing the cancer-agent.

Who can gain from the benefits of vitamin A supplements?

Some people may need to take vitamin A supplement. Examples of people who will benefit are: –

1. People who are unable to see in the dark, or have dry and dull eyes.
2. Kids who have poor growth
3. People who have skin problems.
4. Anyone who are under low skin diet or having poor absorption (like suffering from cystic fibrosis).

Vitamin B12- Multiple Benefits for Every One

You can easily purchase supplements to cover vitamin B. You can get Omega 3 from flax seed oil. Vitamin B12 is incredibly crucial for sensible and usual working of a number of program organs and functions. It is really helpful in your development of red-colored our blood tissues and ensuring a wholesome anxious system. It is incredibly crucial that you aware that deficiency of B12 for even any prolonged period of time can lead to irreversible neurological harm and nerve degeneration.

This water-soluble vitamin is regarded helpful with regards to advertising fatty acid synthesis, DNA synthes is generally and regulation, and power production. It is incredibly crucial that you be aware that this vitamin cannot be produced by vegetation or even creatures as only bacteria possess the needed enzymes which are needed for its synthesis.

Some from the deficiency signs and symptoms consist of breathlessness, listlessness, pallor, and too much tiredness.

Sources of Vitamin B12(foods rich in vitamin B ):

The only reputable and unfortified Vitamin B12 sources are eggs, dairy products, and meat. It is regarded that seaweeds, fermented soya products, and algae are feasible resources of B12. Some from one another resources of vitamin B12 are try to shellfish.

According for the food and nutrition board on the institute of medicine, the suggested dietary consumption for vitamin B12 is:

For infants, among the ages of 0-6 months, the consumption is 0.4 micrograms each day time (mcg/day) and also the Consumption is 0.5mcg/day for infants among the age of seven – twelve months. For youngsters among the ages of 1-3 years, the suggested consumption of B12 is 0.9 mcg/day, the consumption is 1.2mcg/day for Youngsters In your age Set of 4-8 years, and suggested dosage is 1.8 mcg/day for youngsters in your age set of 9-13 years. For males and females of 14 years or older, the recommended Consumption of Vitamin B12 is 2.4 mcg/day.