What they do
VITAMIN A
MAIN SOURCES Liver, oily fish, green leafy vegetables, broccoli, carrots, squash, fruits including apricots and mangoes, and dairy products.
WHAT IT’S FOR Growth, vision and development.
DEFICIENCY Can cause eye inflammation and blindness in low light.
EVIDENCE Most people get enough in their diet and deficiency is rare. But premature infants can have low levels in their first year and people with cystic fibrosis are also more likely to be deficient. High intakes can be harmful and high-dose supplementation with beta-carotene, which converts to vitamin A, has been shown to increase the risk of lung cancer in smokers.
B VITAMINS
All the B vitamins help the body turn carbohydrates into glucose and to metabolise fat and protein.
B1 (thiamine)
ACTION: Aids muscle and nerve function.
MAIN SOURCES: Small amounts in most foods but particularly in whole grains, meat, fish, poultry, eggs, milk, seeds, nuts and vegetables.
DEFICIENCY: Can cause beriberi, weight and appetite loss, confusion, memory loss, muscle weakness and heart problems.
Scientists are studying whether
