Vitamin B2

Vitamin B2 is more commonly known as riboflavin. It was recognized in yeast in 1932 by Dr Otto Warburg and isolated in whey in 1933 by Dr R. Kuhn. It is a water soluble vitamin and easily absorbed by the body. Like most B complex vitamins it cannot be stored by the body and needs regular replacement.

• It stimulates healthy growth and helps repair body tissues.
• It helps the body cells use oxygen.
• It is an aid to the metabolism of carbohydrates, fats and protein.

Unlike vitamin B1, vitamin B2 is not destroyed by heat or oxygen in the air. However, it can be destroyed by light, particularly ultra violet light. Exposure of milk in bottles to sunlight for as little as several hours results in as much as a 10% loss in riboflavin. Light converts vitamin B2 to a substance called luminflavin which in turn destroys vitamin C.

In the cooking process water - not heat - is the problem. B1 is extracted from the food and dissolves in the cooking water. If the water is discarded, so is the vitamin.

B1 is also lost in drips from thawing frozen foods.

Important

• Liver (100g serving)
• Dairy products - full cream/skim milk, yoghurt (250ml serving), cheese (25g serving)
• Cereals - enriched breakfast cereals (30g serving), wheat germ (10g serving), white/wholemeal bread (4 slices)
• Egg (1)
• Lean meat, fish, pulses e.g. cooked soya beans (100g serving)
• Almonds (50g serving)
• Avocado pear (150g/ 1/2 )
• Vegetables - green and leafy e.g. spinach and broccoli (60-100g serving)

Moderate

• Wheat bran (10g serving)
• Nuts (50g serving)
• Lentils, cooked (100g serving)
• Vegetables - beans, cabbage, carrots, peas, cauliflower, potato (60-100g serving)
• Fruit - apples, berries, tropical fruit (100g serving)

Low or Nil

• Fats and oils (trace)

Mild deficiency can increase lines in the skin, particularly round the mouth, in people over thirty.

More serious deficiency can result in skin inflammation and lesions particularly on the lips, tongue and scrotum.

Although vitamin B2 deprived rats have subsequently developed eye cataracts in laboratory tests, studies on vitamin B2 deficient humans have certainly not proved conclusively that cataracts in humans are caused by a deficiency.

While it is possible for a pure riboflavin deficiency to occur in man, a deficiency of this vitamin is found most frequently in conjunction with deficiencies of several other B vitamins.

In Australia vitamin B2 requirements are related to energy intake (kilojoules). The recommendation is 0.12 milligrams per 1000 kilojoules for adults, infants and children.

It is sometimes used to treat ulcers, particularly mouth ulcers.

There are no known toxicity problems.