How much is enough when it comes to B vitamins? Here are recommendations from Johns Hopkins.
B vitamins are vital for the breakdown and utilization of carbohydrates, fats, and proteins, and B vitamins also help to ensure proper functioning of the nervous system and the synthesis of red blood cells and genetic material. Folic acid, one of the B vitamins, is essential during the early months of pregnancy to prevent birth defects, such as spina bifida and cleft palate.
Older adults typically have greater requirements for certain B vitamins, particularly vitamins B6 and B12. Many older people have poor quality diets, and so don’t get enough vitamin B6. And some experts estimate that 10–30% of older adults are unable to absorb vitamin B12 efficiently from food because of alterations in the cells lining the digestive tract or reduced secretion of a substance called intrinsic factor that is needed to absorb vitamin B12. A lack of vitamin B12 can cause a form of dementia that may be mistaken for Alzheimer’s disease, while an insufficient intake of vitamin B6 may impair the function of your immune system.
Recommendations for Intake of B Vitamins
- Get plenty of folic acid everyday. The RDA for this vitamin is 400 micrograms (mcg). Good sources include enriched breads and cereals, dried peas and beans, oranges, orange juice, green vegetables, and whole grains.
Eat foods rich in vitamin B6. The RDA for vitamin B6 is 1.5 mg for women over age 50 and 1.7 mg for men over age 50 (for adults age 19–50, the RDA is 1.3 mg). Good sources of vitamin B6 include fish, meats, poultry, avocados, and bananas.
Maintain an adequate vitamin B12 intake. The RDA for adults is 2.4 mcg per day. You can meet the RDA mainly by consuming foods with added B12 (such as fortified cereals) or taking a supplement containing B12. Choose a supplement that contains B12 in crystalline form (look for the word “cyanocobalamin” on the label), as it is better absorbed by people over age 50 than other B12 formulations. Vegetarians who eat no animal products (B12 is found in meat, poultry, shellfish, fish, eggs, and dairy products) need to take vitamin B12 supplements; people taking folic acid supplements should also take 1mcg of vitamin B12 daily.
Consult your doctor about whether to take B vitamins in individual supplements or as part of a multivitamin-mineral supplement. Most multivitamin-mineral supplements contain the amounts of folic acid, vitamin B6, and vitamin B12 recommended above.
