Vitamin Deficiencies: An Overview

Abstract

Vitamins are substances that act as coenzymes (enablers) and regulators of metabolic processes. There are 13 known vitamins (vitamins A, B1, B2, niacin, pantothenic acid, B6, folic acid, B12, biotin, C, D, E, and K). Most have to be added to the body via food or supplements. Vitamins A, D, E, and K are fat-soluble while the others are water-soluble. Deficiencies in one or more of the vitamins lead to so-called vitamin deficiency syndromes. This article briefly reviews the symptoms and diseases found in such deficiencies. 1. VITAMIN A (RETINOL, CAROTENE) DEFICIENCY Vitamin A (retinol) is a fat soluble and found in fish liver oils, liver, egg yolks, butter, and cream. Another substance, β-carotene found in vegetables such as carrots, can also be converted to retinol. Vitamin A deficiency is a public health problem in over 100 countries, especially in Africa and South-East Asia. It is the leading cause in the world of preventable blindness in children and raises the risk of disease and death from severe infections. NYCTANOPIA, NYCTALOPIA, NIGHT BLINDNESS: Night blindness may be an early sign of A deficiency. Individuals suffering from night blindness not only see poorly at night, but also require some time for their eyes to adjust from bright light. In addition, contrast vision may also be affected.