Research at Tufts University has suggested that deficient vitamin B6 levels are common in the U.S., and could be reduced via supplementation.

The results come from the NHANES data base, which is one of the largest epidemiological studies to evaluate overall nutrition, as well as B6 levels.

The study found four groups to be particularly deficient in vitamin B6:

1. Women of reproductive age, especially current and former users of oral contraceptives
2. Male smokers
3. African-American men
4. Those over 65

Martha Morris, PhD, an epidemiologist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts noted that "Across the study population, we noticed participants with inadequate vitamin B6 status, even though they reported consuming more than the Recommended Daily Allowance of vitamin B6, which is less than two milligrams per day. The question our study raises is whether, due to aging, genetics, or exposures, some population subgroups need supplements to achieve the current biochemical definition of adequate status."

Vitamin B6 is important for heart health, immune system function and mood, as well as being critical for numerous other functions.

For the purposes of the study, PLP blood levels of less than 20 nmol/L were deemed to be deficient in both men and women. This is the level below which one sees symptoms of deficiency, but is not the level needed for optimal function.

Overall, 11 percent of supplement users and nearly a quarter of non-users demonstrated plasma PLP blood levels of less than 20 nmol/L, with a higher incidence among the sub-groups noted above.

The researchers also noted "Most importantly, the data suggest oral contraceptive users have extremely low plasma PLP[vitamin B6] levels. Three quarters of the women who reported using oral contraceptives—but not vitamin B6 supplements—were vitamin B6 deficient."

I like to tease that the RDAs stands for "Ridiculous Dietary Allowances." The RDAs for vitamin B6 Range from 1.3 to 1.7 mg a day. This study shows that even those levels can result in severe vitamin B6 deficiency.

I personally recommend 85 mg daily of vitamin B6. Do not take more than 250 mg of vitamin B6 daily unless directed by your physician, as significantly higher doses may be associated with nerve injury.