Vitamins
Vitamins are chemical substances that are vital for good health. They are important for many daily bodily functions, such as growth and cell reproduction. Because the body cannot store vitamins a regular intake is important.
Most vitamins are provided by food and are divided into 2 groups.
1. Fat soluble
- Vitamin A (retinol): occurs in liver, oily fish (such as salmon and herring) and full fat dairy products. Carotene in orange and yellow coloured fruit and vegetables and leafy green vegetables is converted to retinol.
- Vitamin D: present in dark fleshed fish and eggs. Our bodies manufacture vitamin D with the help of sunlight.
- Vitamin E: found in a wide variety of plant foods and seafood.
- Vitamin K: from wholegrain cereals and leafy green vegetables.
2. Water soluble
- Vitamin B group: found in many foods including meat, fish, wholegrain cereals and bread, fortified breakfast cereals, pulses (dried beans and lentils), nuts and yeast extract. Vitamin B2 (riboflavin) is found in dairy products and eggs and vitamin B12 in meat.
- Folic acid (folate): found in liver, yeast extract, some fortified breakfast cereals, pulses, wholegrain cereals, nuts, fruit and leafy green vegetables.
- Vitamin C: fresh and frozen fruit and vegetables, particularly soft and citrus fruits.
Fat soluble vitamins, as the name implies, can be stored in fats and hence we tend to maintain adequate levels for longer — up to 2 years — after our intake drops. Any excess of water soluble vitamins is simply excreted in the urine, so the effects of a low intake are seen sooner, although it still generally takes months. Historically, the clearest example of this was scurvy, the result of vitamin C deficiency that would occur when sailors had been at sea for some months without fresh fruit or vegetables.
Most people easily meet their daily vitamin needs by eating a varied diet based on bread, cereals, fruit and vegetables. Some meat, fish, eggs, milk, yoghurt and cheese should also be eaten. While an adequate intake of vitamins is essential for health, taking more than is needed does not usually confer any extra health benefit and can, rarely, be dangerous.
Last Reviewed: 13 February 2009
