What is Vitamin B6?

Vitamin B 6 plays a major role in making proteins, hormones, and neurotransmitters (chemicals that carry signals between nerve cells). Because mild deficiency of vitamin B 6 is common, this is one vitamin that is probably worth taking as insurance.

However, there is little evidence that taking vitamin B 6 above nutritional needs offers benefits in the treatment of any particular illnesses, except, possibly, nausea of pregnancy (morning sickness).

The results of a large double-blind, placebo-controlled study suggest that vitamin B 6 at a dose of 30 mg daily may be helpful for treating nausea in pregnancy (morning sickness). ¹ Vitamin B 6 has been proposed for numerous other uses as well, but without much (if any) scientific substantiation. For example, the two most famous uses of vitamin B 6 , carpal tunnel syndrome and premenstrual syndrome PMS , have no reliable supporting evidence at all, and the best-designed studies found it ineffectivefor either of these purposes. ² Higher intake of vitamin B 6 reduces the level of homocysteine in the blood, a substance that might accelerate cardiovascular disease (heart disease, strokes, and related conditions.) However, there is as yet no meaningful evidence that reducing...

Safety Issues

The safe upper levels for daily intake of vitamin B 6 ³ are as follows:

• Children
• 1-3 years: 30 mg
• 4-8 years: 40 mg
• Males and Females
• 9-13 years: 60 mg
• 14-18 years: 80 mg
• 19 years and older: 100 mg
• Pregnant or Nursing Women
• 18 years old and younger: 80 mg
• 19 years and older: 100 mg

At higher dosages (especially above 2 g daily) there is a very real risk of nerve damage. Nerve-related symptoms have even been reported at doses as low as 200 mg.² (This is a bit ironic, given that B6 deficiency also causes nerve problems.) In some cases, very high doses of vitamin B6 can cause or worsen acne symptoms.⁴

In addition, doses of vitamin B6 over 5 mg may interfere with the effects of...