Vitamin A:Needed for healthy vision, bone growth and a strong immune system.
Available as retinol from animal sources such as eggs, meat (especially liver), butter, milk and oily fish and as beta-carotene from yellow or orange fruits and vegetables, and from leafy greens. Excess retinol in early pregnancy can lead to birth defects.
Vitamin B:Needed for healthy nerve and blood function.
A complex group comprising several vitamins, including folic acid. Good sources include wholegrains, brewer's yeast, dairy and avocados. People with high stress levels may need to up their intake. Some B vitamins taken in excess have been associated with nerve damage.
Vitamin C:Needed for many chemical reactions in the body.
Stock up on vitamin C in fresh fruit and vegetables. Many people swear high doses of vitamin C help fight a cold, but so far the scientific evidence hasn't backed this up. Excess has been associated with nausea.
Vitamin D:Needed for healthy bones and may help protect against cancer.
Not really a vitamin, this is a hormone we can make with the help of UV rays from sunlight. Dietary sources include oily fish. Excess can cause nausea and upset calcium levels in the body. Deficiency is relatively common in Ireland in winter.
Vitamin E:Needed for healthy cell function.
Sources include nuts and green leafy vegetables and wheatgerm. Deficiency is rare. Excess could result in bleeding.
Vitamin K:Needed for blood clotting.
Eat up your leafy greens, cereals and soybeans for this vitamin. Bacteria in your gut will also make it for you. Vitamin K can interfere with blood-thinning medication, such as warfarin.