The complex of B vitamins includes the following group of substances:
B1 – thiamine
B2 – riboflavin
B3 – nicotinic acid
B6 – pyridoxine
B12 – cobalamin
folate – folic acid.
The body requires relatively small amounts of vitamins B1, B2 and B3.
Vitamins B6 and B12 help the body to use folic acid and are vital nutrients in a range of activities, such as cell repair, digestion, the production of energy and in the immune system.
Vitamin B12 is also needed for the breakdown of fat and carbohydrate.
Deficiency of either vitamin will result in anaemia.
Vitamin B6 is found in most foods, so deficiency is rare.
Vegetarians and B12
Vegetarians who eat eggs and dairy produce will get enough B12.
Vitamin B12 deficiency can occur in vegans because all dietary sources are animal in origin.
The British Vegan Society recommends foods fortified with vitamin B12, such as:
soya powder and milk
soya mince or chunks.
The best dietary sources of the B vitamins, especially B12, are:
animal products (meat, poultry)
yeast extracts (brewers’ yeast, Marmite).
Other good sources include:
asparagus, broccoli, spinach, bananas, potatoes
dried apricots, dates and figs
milk, eggs, cheese, yoghurt
nuts and pulses, fish, brown rice, wheat germ, wholegrain cereals.
Dietary sources of vitamin B6 are similar to those for vitamin B12 and also include avocado, herring, salmon, sunflower seeds and walnuts.
Folic acid (folate)
Folic acid works closely in the body with vitamin B12. It is vital for the production of healthy blood cells.
Lack of folic acid is one of the main causes of anaemia, particularly in people whose diet is generally poor.
Vitamins B6 and B12 help the body use folate, so are often given alongside folic acid supplements.
In pregnancy, low folate levels increase the risk of the baby’s spinal cord system not developing completely (spina bifida).
All women are now advised to take folic acid supplements in the first three months of pregnancy and ideally before conception occurs.
Folate occurs naturally in most foods but often in small amounts.
Many food manufacturers now fortify white flour, cereals, bread, corn, rice and noodle products with folic acid.
One serving of each enriched product will contribute about 10 per cent of the RDA for folic acid.
Wholegrain products are not enriched because they already contain natural folate.
Liver contains the greatest amount of folic acid, with lower levels found in beef, lamb and pork and a range of green vegetables and citrus fruits.
Other sources of folate are dried beans, fresh orange juice, tomatoes, wheat germ (wholemeal bread and cereal) and wholegrain products (pasta and brown rice)