Description

Vitamin A is a diverse vitamin that has a wide range of functions. Vision improvement is one positive aspect of vitamin A supplementation (1), Another is bone and body growth which can be improved (2). Immune function is boosted by an increase of white blood cells which can destroy harmful bacteria (3). Epithelial cells require Vitamin A in order to function properly, these cells serve as barriers to infection by bacteria and other sources (4).

Deficiencies

There may be certain signs that you may be deficient in Vitamin A, one of the well known signs is low vision at night or xerophthalmia. Other side effects of vitamin A include Dry/scratchy eyes, rough/dry skin as well as an increased risk of viral infections. Another condition that could develop, if low on vitamin A is hyperkeratosis which is a toughening and thickening of the outer layer of the skin which can result from rubbing, pressure and irritation of the skin which can lead to calluses and corns on hands and feet.

It is recommended that optimal consumption for women is 700 micrograms a day and for men it 900 micrograms in a day  

1 – Rando, R. R. (1990). The chemistry of vitamin A and vision. Angewandte Chemie International Edition in English, 29(5), 461-480.

2 – Mellanby, E. (1947). Vitamin A and bone growth: the reversibility of vitamin A‐deficiency changes. The Journal of physiology, 105(4), 382-399.

3 – Stephensen, C. B. (2001). Vitamin A, infection, and immune function*. Annual review of nutrition, 21(1), 167-192.

4 – Batourina, E., Choi, C., Paragas, N., Bello, N., Hensle, T., Costantini, F. D., … & Mendelsohn, C. L. (2002). Distal ureter morphogenesis depends on epithelial cell remodeling mediated by vitamin A and Ret. Nature genetics, 32(1), 109-115.