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What are Fat-Soluble Vitamins? The Differences Between Fat-Soluble and Water-Soluble Vitamins

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Taking vitamin supplements can help to replenish vitamins that may be low because of an unbalanced diet.

Taking vitamin supplements can help to replenish vitamins that may be low because of an unbalanced diet.

What is the difference between fat-soluble and water-soluble vitamins?

Vitamins are generally classified into two groups: fat-soluble vitamins and water-soluble vitamins. The fat-soluble vitamins are vitamins A, D, E, and K, and are stored in body fat and reach toxic levels. Water-soluble vitamins are B-complex vitamins and vitamin C. The water-soluble vitamins are generally not stored in any significant amounts in the body, so they need to be included in the diet on a daily basis. In healthy individuals, deficiencies in fat-soluble vitamins are rarer than deficiencies in water-soluble vitamins.

The absorption of fat-soluble vitamins in enhanced by dietary fat. Individuals who are afflicted with malabsorption of fat or who consume an extremely small amount of fat are at higher risk for development of fat-soluble vitamin deficiencies. Fat-soluble vitamins are generally more stable than water-soluble vitamins and are less prone to destruction by heat, air, and light.

Fat-Soluble Vitamins

Fat-soluble vitamins are vitamins A, D, E, and K. They are stored in the fatty tissue of the body and are more stable than their water-soluble cousins.

Since an excess of these vitamins are stored in the body and do not pass through the body (such as water-soluble vitamins) it is possible to experience negative health effects from too high of an intake of these vitamins.

Carrots are a good source of Vitamin A.

Carrots are a good source of Vitamin A.

Vitamin A

Vitamin A can be found in two forms: carotene and vitamin A. Preformed (or retinol). Carotene is found in dark, leafy green vegetables and deep orange vegetables (with the exception of oranges). Retinol is found in animal products such as liver, milk fat in whole milk and cream, butter, and egg yolks.

Although it is necessary to ingest meat to obtain retinol, carotene is processed into vitamin A in the liver, which means that vegans and vegetarians are in no danger of forming a vitamin A deficiency so long as they include dark leafy green and dark orange vegetables in their diet.

Vitamin A Deficiency

Vitamin A is important for healthy epithelial tissue, which is the external skin and internal lining of the respiratory and gastrointestinal tract. A deficiency in vitamin A can, therefore, impair the intestinal tracts ability to absorb nutrients by flattening the villi. It increases the risk of infection and has been associated with night blindness in many countries. Vitamin A helps with bone growth, a healthy immune system, improved vision, and reproduction. A rare cause of hypocalcemia, or excess calcium in the blood, has been associated with an excess of vitamin A.

There are plenty of foods that are rich in vitamin D.

There are plenty of foods that are rich in vitamin D.

Vitamin D

Vitamin D has many physiological roles beyond those related to bones, including regulating blood pressure and acting as a tumor suppressant. It aids in the absorption of calcium and phosphorus, regulates the blood levels of calcium, and promotes bone and teeth mineralization.

Vitamin D Deficiency:

Vitamin D deficiency leads to secondary hyperparathyroidism, increased bone turnover, bone loss, and when severe, osteomalacia. Hypovitaminosis D is a condition of low vitamin D status and is associated with an impaired neuromuscular function. Hypovitaminosis D is prevalent even in southern latitudes that have increased sun exposure and should be taken into account in the evaluation of postmenopausal and male osteoporosis.

Vitamin D deficiency can also lead to problems with muscle function and has been associated with tuberculosis, rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases, hypertension, diabetes, and specific types of cancers.


Marlene Bertrand from USA on July 29, 2015:

I never really knew the difference. This adds to my knowledge of vitamins and now I see how some vitamins can become toxic.

Lamin on January 29, 2015:

lack of protein or enaistesl fatty acids causes hair loss.A lack of Protein is important for the growth of strong hair and nails. Most people on a non-vegan diet rarely suffer from protein deficiency as nearly all foods contain a certain amount of protein.Foods containing Protein Grains, legumes (peas, beans and lentils), nuts, seeds, and vegetables. A deficit in Fatty acids could also be causing hair loss. Omega-3 fatty acids are vitally important although a bit scarce in most peoples diets.Foods containing Omega-3 Fatty Acids-Tofu, canola oil, and walnuts, as well as others. The richest vegan source of omega-3 fatty acids can be found in flaxseed oil which is available in natural food stores (refrigerated). Flax oil is a pure vegetable fat and, like all fats, should be used in moderation drizzled over salads, potatoes and vegetables.I hope this is useful, take care and stay safe,x

Matei on January 26, 2015:

Your answer lifts the ingeilltence of the debate.

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