Vitamins can be classified based on their solubility. Some vitamins are water-soluble and others are fat-soluble. Fat-soluble vitamins are similar to oil and they do not dissolve in water. The four fat-soluble vitamins are vitamins A, D, E, and K. Fat-soluble vitamins are most abundant in high fat foods and they are much better absorbed into your bloodstream when you eat them with fats. Small amounts of vitamins are required in the diet to promote growth, reproduction, and health.
Vitamin A is not a single vitamin, but a collection of compounds known as retinoids. They occur naturally in the human body, and they are also present in some dietary sources. Some foods provide retinols, which the body can use directly as Vitamin A. Furthermore, Vitamin A is needed for the maintenance of normal mucous membranes and for normal vision. It occurs naturally in animal food products such as butter, whole milk, liver and egg yolks, but the body converts certain carotenoids, especially β-carotene, to Vitamin A.
Vitamin D is commonly called a “sunshine vitamin” and is produced when you expose your skin to sunlight. The active form of Vitamin D promotes intestinal absorption of calcium and phosphorus, and it influences bone mineralization. It benefits bone health by promoting the absorption of these minerals and it also supports the immune system. Vitamin D comes in two main dietary forms, the Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Ergocalciferol is produced commercially by ultraviolet (UV) irradiation of the plant sterol ergosterol and cholecalciferol is formed by the action of sunlight on the precursor of 7-dehydrocholesterol in the skin. Vitamin D occurs naturally only in animal foods such as liver, butter, fatty fish and egg yolks.
Moreover, Vitamin E is an important antioxidant that can help the body destroy free radicals. Free radicals are unstable atoms that can cause oxidative stress. It is a kind of stress that can lead to cell damage, and this can result in cancer as well as other diseases. Vegetable oils are the richest source of Vitamin E. Other good sources include nuts, seeds, whole grains, and wheat germ. The vitamin E content of animal foods is generally low. Vitamin E may help boost the immune system, dilate the blood vessels and help prevent clotting.
Vitamin K helps the body form blood clots. Blood clotting is essential to prevent excessive bleeding. Aside from blood clotting, it also lowers the risk of heart disease, enhance bone health and reduce the buildup of calcium in the blood. We can obtain vitamin K from dietary sources as well as through synthesis by the guts of microflora. Larger amounts of Vitamin K are present in dark-green leafy vegetables; lower levels are found in cereals, dairy products, meats, and fruits. All of these fat-soluble vitamins are essential for health and play important roles in the body. To prevent deficiency, make sure that you get all the fat-soluble vitamins in adequate amounts.
- PNFP Rowence F. Zorilla, RND
References:
1. What are fat-soluble vitamins?
Medically reviewed by Natalie Olsen, R.D., L.D., ACSM EP-C — Written by Jenna Fletcher on January 17, 2020
https://www.medicalnewstoday.com/articles/320310#vitamin-e
2. Fat-Soluble Vitamins
https://www.ncbi.nlm.nih.gov/books/NBK218749/
3. The Fat-Soluble Vitamins: A, D, E, and K
Written by Atli Arnarson BSc, PhD — Medically reviewed by Grant Tinsley, PhD, Nutrition — Updated on January 11, 2022
https://www.healthline.com/nutrition/fat-soluble-vitamins#vitamin-a
