Catherine Saxelby's Foodwatch | Glossary

Occurs as retinol and beta-carotene. Essential for vision, growth and healthy mucous membranes of the mouth, respiratory and urinary tract. Excess intakes of vitamin A are stored in the body and can be harmful.

Eight vitamins which function similarly, occur together in cereal grains, vegetables, lean meats and milk and are soluble in water.

(Thiamin). Acts to release energy from carbohydrate and maintain the nervous system. In Australia, deficiency occurs largely in alcoholics.

Cobalamin. A B vitamin found only in animal foods and likely to be borderline in long-term, strict vegetarians. Required for the formation of red blood cells — deficiency leads to pernicious anaemia — and utilisation of protein, fat and carbohydrate.

(Riboflavin). Required for healthy skin, nails, hair and eyes, it forms part of several enzymes involved in energy metabolism.

(Pyridoxine). Critical for protein and amino acid metabolism. Rarely deficient in normal diets.

(Ascorbic acid). Essential vitamin which plays a primary role in the formation of collagen, bones, blood vessels and connective tissues. It is required for wound healing and increases the body's absorption of iron. Smokers have an increased requirement for vitamin C. Megadoses of vitamin C have been hailed as a cure for the common cold, but carefully controlled studies have shown it can reduce the severity, but not eliminate colds entirely.

(Cholecalciferol). Formed by the action of sunlight on the skin, vitamin D enables calcium to be absorbed into bones. Cod liver oil, the richest food source, was once given as a regular supplement in northern European countries with their long dark winters, but is unnecessary in

(Alpha-tocopherol and related substances). Found in vegetable oils, eggs, grains, green vegetables and nuts. Functions as an antioxidant protecting oils from rancidity and is under study for its role in preventing heart disease

Essential for the production proteins involved in clotting of the blood. Vegetables, eggs and liver are the main dietary sources.

Substances necessary for life which regulate our bodies' metabolism. Except for three, they cannot be synthesised by our bodies so must be obtained from food.