Vitamins A and C: their function and structure explained

This first article in a series on the role of vitamins and minerals explains the structure and function of vitamins A and C, which are needed for healthy skin and a healthy immune system. Vitamin A is obtained pre-formed in food or synthesised by the body from beta-carotene, which is present in many coloured fruits and vegetables. It is essential to ocular health and function, and deficiencies are associated with night blindness. Vitamin C is water soluble and cannot be manufactured by the body. Dietary sources include citrus fruits and many other fruits and vegetables. Chronic vitamin C deficiency causes scurvy, which predominantly relates to abnormal collagen production.

This article has been double-blind peer reviewed

In this article…

• The role vitamin A plays in vision, and the effects of deficiencies on ocular health and function

• How vitamin A maintains epithelial integrity and immune function

• The effect of vitamin C on collagen production and what causes scurvy

Key points

Vitamin A is fat soluble and can be obtained directly or indirectly from food

A deficiency of vitamin A can cause night blindness

Humans cannot synthesise vitamin C so must obtain it directly from their diet

Vitamins A and C are essential for maintaining healthy skin and a healthy immune system

Chronic vitamin C deficiency may result in scurvy