1.5 Vitamins | The chemistry of life

1.5 Vitamins (ESG4H)

This section should be linked to the digestive system and healthy diet that were covered in Grade 9 Natural Sciences. Vitamins are organic compounds required by organisms as vital nutrients in limited amounts. Vitamins are therefore essential to a balanced diet. The sources, functions and deficiency diseases of the main vitamins should be revised.

Vitamins are organic compounds required by organisms as vital nutrients in limited amounts. Vitamins are therefore essential to a balanced diet. Vitamins have a variety of functions in the body. Some vitamins are coenzymes, which means that they help enzymes to catalyse a reaction efficiently. Some are responsible for regulating metabolism or act as regulators of cell and tissue growth and differentiation.

Vitamin	Role	Food sources	Deficiency disease
Vitamin A	Needed for proper functioning of eyes	liver, carrots, egg	night blindness
Vitamin B (A group of vitamins with related functions)	Carbohydrate, protein, lipid, nucleic acid and alcohol metabolism; neurotransmitter synthesis and nerve function; red blood cell production	grains, potatoes, bananas	B1- beriberi, B3- pellagra, B6, B9, B12- anaemia
Vitamin C	Involved in iron metabolism; plays a role in the immune system; helps with the formation of collagen for wound repair	citrus fruit (oranges, lemons etc), tomatoes	scurvy (results in bleeding gums)
Vitamin D	Important in absorption of minerals from the gut (such as calcium and phosphate); works together with calcium and phosphorus in bone / teeth hardening	full cream milk, oily fish	rickets (resulting in soft bones, with bowed legs and widened wrists)
Vitamin E	Acts as an anti-oxidant	margarine, soybean oil, fortified cereals, condensed cow's milk, cheese, orange juice	depressed immune system, anaemia, poor nerve conduction

Figure 1.22: Sources of essentials vitamins.

1.4 Organic compounds

Table of Contents

1.6 Recommended Dietary Allowance