What is the RDA?
The RDA (recommended dietary [or daily] allowance) is the amount of each vitamin that people need every day. Apart from some or all of the necessary amount of vitamin D (made in skin exposed to sunlight) and some or all of the necessary amount of vitamin K (made by friendly bacteria in the gut), the RDA of vitamins must come from the diet.
The recommended requirements change from birth to old age (see ‘Do Our Vitamin Requirements Change as We Age?’). The RDAs in this article are based on a World Health Organisation report published in 2004.
Water-Soluble VitaminsBecause these are not stored in the body, people must eat food containing the full RDA of these vitamins every day.
Vitamin B1 (thiamine)Adults need 1.1-1.2 mg/day of vitamin B1. This is about a third of a cup of rice bran or wheat germ cereal, three cups of cooked peas or a cup of sunflower seeds with hulls.
Vitamin B2 (riboflavin)Adults need 1.1-1.3 mg/day of vitamin B2. This would be about four cups of skimmed milk or 250 g of cheese.
Vitamin B3 (niacin)Adults need 14-16 mg/day of vitamin B3. This is about eight tablespoons of peanut butter, 225 g of white chicken meat, or a just over a pint of passion fruit juice.
Vitamin B5 (pantothenic acid)Adults need 5.0 mg/day of vitamin B5. This is two medium avocados, or about 75 g of sunflower seed kernels.
Vitamin B6 (pyridoxine)Adults need 1.3-1.7 mg/day of vitamin B6. This is about four bananas or 225 g of cooked salmon.
Vitamin B7 (biotin)Adults need 30 mcg/day of vitamin B7. This is about 75 g of liver or one to two eggs.
Vitamin B9 (folic acid)Adults need 400 mcg/day of vitamin B9. This is about 50g of chicken liver, just over a cup of lentils, a pint and a half of orange juice or 135 g of breakfast cereal.
Vitamin B12 (cyanocobalamin)Adults need 2.4 mcg/day of vitamin B12. This is about 90 g of baked salmon, four eggs or 100 g of cooked beef.
Yeast extract is a rich source of B vitamins.