AUTHOR Dr. Carlos Orozco (BSc, MSc, ND, MD, PhD, FPAMS).
Vitamins are crucial for metabolic function. They are organic compounds that need to be taken from the diet because the human body is unable to produce them.
Vitamin A is a family of fat-soluble organic compounds that play an important role in vision, bone growth, reproduction, cell division, and cell differentiation. It consists of three biologically active molecules: retinol, retinal (Trans and Cis) and retinoic acid.
Signs and Symptoms of Deficiency:
Deficiency of Vitamin A results in the manifestation and expression of acne, rough dried skin, hyperkeratosis, dry hair, decreased tearing, poor sense of taste and smell, sinusitis, poor bone growth, poor and impaired immunity, involution of the thymus, allergies, tinnitus, cysts on endocrine glands, corneal ulceration, inflammation of the eye, night blindness, retardation of growth, weight loss, decrease in corticosteroid production, nephritis, Bitot’s spots whichare due to the buildup of keratin located superficially in the conjuntiva of the eye, which are oval, triangular or irregular in shape. In 1863, Pierre Bitot (1822-1888), a French physician, first described these spots.
The symptoms of deficiency correlate well with the metabolic action of vitamin A.
- Bone development: Formation of chondroitin sulphate in cartilage.
- Growth retardation: Effect on steroidogenesis, bone growth and cell membrane structure.
- Keratinisation: Effect on mucopolysacharide biosynthesis.
- Visual disorders: Absence of retinine precursors.
The deficiency of vitamin A may contribute to proliferative and immune disease. Since vitamin A is important for connective tissue integrity, the effects of deficiency may extend via the basement membrane to all structures coated by connective tissue such as the endothelium, the mesothelium and neuroglia.