Role of Vitamin B in Good Nutrition

Each B vitamin has its own individual properties and its own unique biological role to play. As a group, these nutrients have so much in common that they are often thought of as a single entity.

Key Functions

• B vitamins help the body use energy and are necessary for the metabolism of carbohydrates, proteins and fats.
• B vitamins are utilized as coenzymes – components of enzymes – which speed up biological and chemical reactions in the body.
• The B vitamins thiamin, riboflavin, niacin, pantothenic acid, and biotin help mediate the release of energy from carbohydrates, fats and proteins.
• Vitamin B-6 assists enzymes that metabolize amino acids.
• Folate and vitamin B-12 help cells to multiply, a function that is particularly important to cells with a short life span and that are replaced rapidly, such as red blood cells and the cells lining the gastrointestinal tract.

Food Sources

Whole grains* (wheat, oats, and rye), liver, green leafy vegetables, meats, poultry, fish, eggs, nuts and beans.

*Most of the B vitamins are removed when the grains are highly refined and processed.

Usage

Check with your local market for the recommended daily intake of vitamin B.

Safety Evidence

Each of the B vitamins has different safety and usage factors:

• Vitamin B1 – Easily destroyed by alcohol consumption, caffeine, stress, and smoking. Pregnant women may benefit from slightly higher levels of B1.
• Vitamin B2 – Absorption or availability is decreased by the use of oral contraceptives, as well as by regular exercise and alcohol consumption. Vegetarians and the elderly may benefit from slightly higher levels of B2.
• Nicotinic acid (niacin) – People who exercise regularly, take oral contraceptives, or have a lot of stress in their lives may need slightly higher levels.
• Vitamin B6 – Pregnant or breastfeeding/lactating women, those who use contraceptives or hormone replacement therapy, and those who use antibiotics regularly may need slightly higher levels. B6 supplementation is also suggested for those who consume alcohol, smoke, and consume protein above recommended levels.
• Folic acid – Elderly people and pregnant women may need higher levels, as well as people who consume alcohol or have risk factors associated with heart disease.
• Vitamin B12 – Strict vegetarians and vegans, along with pregnant and/or lactating women, and those who consume alcohol or smoke may need increased levels.
• Biotin – Pregnant women and those who use antibiotics on a long-term basis may need increased levels.
• Pantothenic acid – Elderly people and those who take oral contraceptives, as well as those who smoke, or consume alcohol or caffeine may need slightly higher levels.