The Nutrition Information Centre of the
University of Stellenbosch (NICUS)
Nutrients
Vitamins
Vitamins are essential nutrients required in very small amounts and serve as facilatators for normal metabolism, growth and physical well being. Most vitamins are not made in the body so they must be obtained from the diet.
The 13 major vitamins are found in a wide range of foods and each has a different function in the body. Many are essential for the biochemical processes within our cells and tissues. Vitamins are either fat soluble or water soluble.
Fat-soluble means they dissolve in fat and unsued supplies can be stored in the body. Water-soluble vitamins dissolve in water and cannot be stored in the body. Therefore we need a daily supply from the diet.
Fat-soluble vitamins
See details for: Vitamin A | Vitamin D | Vitamin E | Vitamin K
Vitamins
|
Major Functions |
Sources |
|
Vitamin A
| Plays an essential role in: - - eye health
- normal growth and development
Helps with the body's immune function
Aids the body's reproductive system | Liver
Kidney
Fortified margarine
Yellow and dark green leafy vegetables and fruit
Apricots |
|
Vitamin D
| Plays an essential role in: - - maintenance of the calcium and phosphorus balance
- normal cell growth and function
- in the functioning of several organs including skin, muscles, pancreas, nerves and the immune system
| Fish liver oils
Fortified milk
Fortified margarine
Liver
Egg yolk
Salmon
Tuna
Sardines
Sunlight |
|
Vitamin E | Has antioxidant properties which help maintain healthy cells and protects against conditions such as ageing, air pollution, arthritis, cancer, cardiovascular disease, cataracts, diabetes and infection | Wheat germ
Vegetable oils
Green leafy vegetables
Egg yolk
Nuts |
| Vitamin K | Plays an essential role in: - Making of blood-clotting proteins and a blood protein that regulates blood calcium levels
| Bacterial synthesis in digestive tract
Liver
Leafy green vegetables |
Water-soluble vitamins
See details for: Thiamin | Riboflavin | Niacin | Vitamin B6 | Folate | Vitamin B12 | Pantothenic acid | Biotin | Vitamin C
Vitamins
| Major Functions | Sources |
Thiamin
Vitamin B1 | Is part of a coenzyme used in energy metabolism Supports normal appetite and functioning of the nervous system | Widespread in foods
Lean pork
Lean beef
Liver
Wheat germ
Whole grains and enriched breads and cereals
Legumes |
|
Riboflavin
| Plays an essential role in: - conversion of nutrients into their functional forms
- communication between cells
May play a role in the prevention of damage to cells | Milk
Liver
Brewer's yeast
Meats
Green leafy vegetables
Fortified cereals |
| Niacin | Plays an essential role in: - metabolism of carbohydrates, fatty acids and amino acids
- respiration within cells
| Meats
Poultry
Fish
Peanuts
Brewer's yeast |
Pyrodoxine
Vitamin B6 | Helps the body to use proteins as building blocks Is essential for healthy blood Helps to maintain a healthy nervous system Maintains normal brain-function | Fortified cereal
Dried beans
Peanut butter
Potatoes
Liver
Milk
Eggs
Bananas |
Folate
| Forms part of various coenzymes used in cell synthesis
| Leafy green vegetables
Legumes
Seeds
Liver |
Vitamin B12
Cobalamin | Forms part of coenzymes used in cell synthesis Helps to maintain nerve cells Reforms the folate coenzyme Meat | Fish
Poultry
Shellfish
Milk
Cheese
Eggs |
| Pantothenic Acid | Forms part of Coenzyme A, used in energy metabolism | Widespread in foods |
| Biotin | Forms part of a coenzyme used in energy metabolism, fat synthesis, amino acid metabolism, and glycogen synthesis | Widespread in foods
|
Vitamin C
Ascorbic Acid | Has antioxidant properties which help to protect against damage done to cells
Is involved in several enzyme systems for the:
- synthesis of collagen (connective tissues, cartilage, teeth and skin)
- the healing of wound
- conversion of nutrients into their functional forms
Promotes resistance to infection Protects lung functioning | Citrus fruit
Strawberries
Tomato
Peppers
Cabbage
Guava
Potato
Paw-paw (Papaya)
Broccoli |
A varied diet based on wholegrains, fruit and vegetables, should provide all the nutrients essential for health.
Some individuals are at high risk for vitamin deficiency and have higher individual needs for vitamins which will not be covered by diet alone.
