Originally thought to be a single vitamin compound, the B vitamins are a family of eight different vitamins, including thiamine, riboflavin, niacin, folate, vitamin B6, vitamin B12, pantothenic acid and biotin. Each different B vitamin performs its own function in your body and carries its own recommended daily dosage.
The recommended dietary allowance, or RDA, for thiamine is 1.1 mg per day for women and 1.2 mg per day for men. Thiamine plays a role in the transmission of nerve impulses and helps metabolize carbohydrates and certain amino acids. The best sources of thiamine include enriched breads and fortified cereals.
Adult women require 1.1 mg of riboflavin daily; adult men should consume 1.3 mg per day. Riboflavin helps turn carbohydrates, proteins and fats into energy you can use and enhances the function of two other B vitamins, vitamin B12 and niacin. The best sources of dietary riboflavin include milk and yogurt.
The RDA for niacin is 14 mg per day for adult women and 16 mg per day for adult men. Niacin allows your body to synthesize fats and cholesterol and helps riboflavin turn fats, protein and carbohydrates into energy. Meat, fish, poultry and enriched cereals are the best sources of niacin.
Adult men and women should aim to consume 400 mcg of folate per day; pregnant women, however, require 600 mcg daily. Folate is vital for DNA synthesis and helps prevent certain birth defects, called neural tube defects, in a developing fetus. Folate is found in legumes, leafy green vegetables and enriched breads and cereals.
The Food and Nutrition Board provides recommendations for vitamin B6 in ranges. Adult women should consume 1.3 to 1.5 mg of vitamin B6 daily; adult men should consume 1.3 to 1.7 mg per day. Vitamin B6 acts as a coenzyme, allowing enzymes to produce chemical reactions in your body; it helps to break down glycogen, the storage form of glucose. A large variety of foods, including meat, fish, poultry, dairy products, eggs and enriched cereals, contain vitamin B6.
Adults require 2.4 mcg of vitamin B12 per day. Vitamin B12 helps your body to create healthy red blood cells and keeps your nerve cells and tissues healthy. The only sources of naturally occurring vitamin B12 are meat, fish, poultry and dairy products.
Pantothenic Acid and Biotin
Adults require 5 mg of pantothenic acid and 30 mcg of biotin per day. Like several other B vitamins, these two vitamins work together to turn carbohydrates, protein and fats into energy. Pantothenic acid and biotin are widely available in whole grains, nuts, legumes, nut butters, meat, milk and eggs.