Vitamins are needed by the body in only small quantities, however, they are vital for the body to function properly. There are two categories – water soluble vitamins and fat soluble vitamins. Water Soluble Vitamins – are vitamins that are not stored in the body therefore you need them on a daily basis from your diet. Fat Soluble Vitamins – are vitamins that are stored in the body, usually in the liver and fatty tissues. They tend to be found in foods containing fats. Although we use these vitamins on a daily basis we don’t need them from our diet every day.
Thiamin (vitamin B1)
Thiamin, along with the B group of vitamins, is required for releasing energy from carbohydrates and fats. It is also important for nerve and brain function. Thiamin is found in roots and tubers such as potatoes and unrefined cereal products such as wholegrain bread, also pork, liver, eggs, nuts, seeds and peas. Fortified breakfast cereals and bread also provide a good source of thiamin.
Riboflavin (vitamin B2)
Riboflavin is required for the release of energy from carbohydrates, fats and protein. It is also important for keeping the skin, eyes and nervous system healthy. The main sources are dairy products, eggs, meat and poultry, also green vegetables such as asparagus, broccoli and spinach. Fortified breakfast cereals are also a source of riboflavin.
Niacin (vitamin B3)
Niacin is important for energy metabolism. Food sources include oats, rice and wheat, also milk and eggs. Meat in general is a good source of niacin. This vitamin can be made from tryptophan in humans, an amino acid.
Pathothenic acid (vitamin B5)
This vitamin is found in most plant and animal foods and is involved in fat and carbohydrate metabolism. Major food sources are chicken, beef, liver, kidneys, eggs, also plant foods such as tomatoes, potatoes, legumes (beans, lentils, peas, peanuts), oats and whole grains.
Vitamin B6 is also called pyridoxine and is required to help the body use up and store energy from the metabolism of carbohydrates and protein. It is also essential for the formation of red blood cells. Vitamin B6 can be found in abundance in bananas, potatoes, whole cereals such as oats, pulses, meat, fish, milk and eggs.
Vitamin B12 (cyanocobalamin)
Vitamin B12 is involved in the metabolism of folate. It is found only in food of animal origin e.g. meat, milk, cheese, eggs etc therefore vegetarians and particularly vegans are susceptible to vitamin B12 deficiency anaemia and are therefore recommended to take a vitamin B12 supplement.
Folate (folic acid)
This vitamin is one of the B group vitamins and works together with vitamin B12 for the production and maintenance of DNA, red blood cells and cell division. Naturally occurring folate is found in small amounts in the following foods – green leafy vegetables (especially sprouts, broccoli, spinach, green beans, peas), potatoes, fruit (especially oranges), brown rice, milk and dairy products. As folic acid, it is found in fortified breakfast cereals and breads and yeast extract. Folic acid has been found to reduce the risk of neural tube defects such as spina bifida and therefore supplements of 400mcg are recommended for all pregnant women up until the 12th week of pregnancy and women who are planning to have a baby. This B vitamin is involved in fatty acid synthesis and metabolism. It is found in liver and kidneys, egg yolk and yeast.
Vitamin C (ascorbic acid)
This vitamin is found in a wide variety of fruit and vegetables. Rich sources are citrus fruits, berries, peppers, parsley, blackcurrants and leafy green vegetables. It is important for the structure of bones, cartilage, muscle and blood vessels. It also helps wound healing and iron absorption. It has antioxidant properties which can protect the cells from damage by oxygen, which may lead to heart disease and cancer.
Vitamin A is important for many functions including maintaining and repairing tissues, growth and development and for a healthy immune system. There are two types of vitamin A – retinol and beta-carotene. You can find retinol in animal based foods such as liver, dairy products (milk, cheese and yoghurt) and oily fish such as sardines, tuna and pilchards. You can find beta-carotene in plant foods such as dark green leafy vegetables such as broccoli, kale and spinach and yellow, orange and red fruits and vegetables such as tomatoes, carrots, squash, oranges and apricots.
Vitamin D promotes calcium absorption from food and therefore is essential for healthy bones and teeth. It also helps maintain heart action and the nervous system. Only a few foods contain vitamin D – fortified margarines and spreads, oily fish such as pilchards, mackerel and salmon, egg yolk and fortified breakfast cereals. Most of our vitamin D is made in the body by the action of sunlight on our skin. Certain groups of the population may be more at risk of inadequate vitamin D and these include pregnant and breastfeeding women, babies and young children, older people aged 65 years or more, people with darker skin such as people of South Asian, African and African-Caribbean ethnicity and people who are not exposed to much sun. The UK Department of Health recommends supplements for these population groups.
Plant oils, nuts and seeds and wholegrains are the main sources of vitamin E. It exhibits antioxidant properties and therefore helps maintain the structure of cells.
Vitamin K is essential for normal blood clotting and is found in dark green leafy vegetables, and plant oils. Smaller amounts are found in dairy foods and meat. This vitamin is also made by bacteria in the small intestine and therefore contributes to the requirement of vitamin K.