Can I Get Too Much Folic Acid And Vitamin B?

There is no one vitamin B, but instead a group of B-complex vitamins. Folic acid, also known as folate, belongs to this group. Many of these water-soluble vitamins are nontoxic, which means that taking high doses should have no adverse effects. Other B-group vitamins, however, should not be taken in excess of of the upper-intake levels recommended by the Food and Nutrition Board of the Institute of Medicine. Folic acid is one B-group vitamin that can be problematic when taken in excess. Getting the right amounts of all these vitamins is important for good health. Talk with your primary-care physician about the amounts you should be getting.

B-vitamins Without Established Upper Limits

The Food and Nutrition Board has not established upper-intake limits for the B-group vitamins thiamin, riboflavin, pantothenic acid, biotin and vitamin B-12. No well-established cases of toxicity have been associated with these vitamins.

Folic Acid

Folic acid is the synthetic B vitamin found in supplements and fortified foods. When the vitamin occurs naturally in foods, it's called folate. Although there are no major concerns about folate, high doses of folic acid can mask a vitamin B-12 deficiency. Therefore, the upper-intake limit for folic acid is 1,000 mcg. This adverse effect has mostly been seen mostly with doses of 5,000 mcg or more, according to the Linus Pauling Institute. The suggested intake for men and nonpregnant women is 400 mcg. Pregnant women should take 600 mcg daily.

Niacin

Niacin supplementation can also be problematic. Too much of the synthetic form can call flushing, a rash and other skin conditions. Another major concern with very high dosage is liver-cell damage. This can occur at doses of 750 mg daily. The recommended dosage for men is 16 mg daily, while women should take 14 mg. Adults should take no more than 35 mg daily.

Vitamin B-6

According to the Linus Pauling Institute, vitamin B-6 in doses of 500 mg to more than 1,000 mg daily can cause sensory neuropathy. Symptoms include pain and numbness in the arms and legs. Take no more than 100 mg of this B-vitamin daily. The daily requirement for vitamin B-6 is 1.3 mg for adults up to age 50.