Vitamin A Deficiency and Toxicity Symptoms

Kale is high in vitamin A and can help prevent vitamin A deficiency.
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The foods you eat every day must provide the nutrients you need to thrive. One of those nutrients is vitamin A, which is one of the fat-soluble vitamins. Vitamin A is essential for good vision, regular cell division, and normal reproduction. It's not too difficult to get enough vitamin A because it's found in many different foods.

Different Foods and Different Forms

Vitamin A is found in a variety of foods, but the animal version is not the same as the version found in plants.

The form of vitamin A found in foods of animal origin is called retinol, or pre-formed vitamin A. It's the most active form, and your body can convert it into retinal or retinoic acid, two additional active forms of vitamin A. Sources of retinol include dairy products, eggs, liver and fortified foods.

The forms of vitamin A found in plants are called provitamin A carotenoids. The best-known carotenoids are beta-carotene, alpha-carotene, and beta-cryptoxanthin. Your body converts these carotenoids to retinol, and they are also thought to be antioxidants that may protect your body from free-radical damage. The best sources of carotenoids are brightly colored and dark green vegetables including carrots, spinach and kale, and fruits like apricots, papaya, and mango.

Vitamin A Deficiency Symptoms

It's not likely the average person will become deficient in vitamin A because it's found in so many foods.

But, chronically not getting enough Vitamin A will cause night-blindness, which is a decreased ability to see in dim light. Another symptom is diminished immune system function, which means your body will have difficulty fighting infections.

Vitamin A deficiency due to poor diet is rare in developed countries and is more likely to result from inflammatory diseases that damage the digestive tract and prevent absorption, such as Crohn's disease and celiac disease.

Alcoholism, zinc deficiency and pancreatic diseases can also affect the amount of vitamin A in the body.

If you have these symptoms, you need to see a health care provider who can order blood tests to determine if a vitamin A deficiency is the problem or if there are other causes.

Can I Get Too Much Vitamin A?

Absolutely, you can get too much vitamin A if you're not careful. It's one of the fat-soluble vitamins, which your body can store it for a long tine. Supplements are rarely needed and can actually be dangerous if the amount of vitamin A builds up.

The tolerable upper limit of vitamin A in adults in 10,000 micrograms. Consuming enormous amounts of vitamin A supplements can result in headaches, dizziness, nausea, vomiting and visual problems.

Hypervitaminosis A is a condition that occurs when your body builds up too much vitamin A over time and can lead to liver problems, weakened bones, and birth defects.

The carotenoids are sold as dietary supplements with the notion they will function as antioxidants, and they are considered to be safer than preformed vitamin A supplements because the body will slow down the conversion from carotenoid to vitamin A as the body stores fill.

However, large doses of carotenoids will give your skin an orange color. Research has shown mixed results on the safety and efficacy of carotenoid supplements, so it's probably best to get your carotenoids from a healthy diet instead taking dietary supplements.

Sources:

Merck Manual - Professional Version. "Vitamin A." Accessed February 19, 2016. http://www.merckmanuals.com/professional/nutritional-disorders/vitamin-deficiency-dependency-and-toxicity/vitamin-a.

Office of Dietary Supplements, National Institutes of Health. "Dietary Supplement Fact Sheet: Vitamin A and Carotenoids." Accessed February 19, 2016. http://ods.od.nih.gov/factsheets/vitamina.

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