Elevated vitamin B6 levels may protect DNA from oxidative damage

A new study from Japan reports that increased blood vitamin B6 concentrations in men may reduce oxidative stress potentially damaging DNA.

In the observational study, blood concentrations of vitamin B6, folate and a marker of oxidative stress
(8-hydroxy-2'-deoxyguanosine, 8-OHdG) of 500 men and women aged between 21 and 66 were measured (1). The study results showed that higher levels of vitamin B6 were associated with lower concentrations of the marker in men who did not smoke and did not drink a lot of alcohol.

The researchers commented that there is biological plausibility for vitamin B6 to protect against oxidative DNA damage: data from animal studies has shown that insufficient or deficient vitamin B6 levels may decrease levels of the antioxidant glutathione, which subsequently increases 8-OHdG. Earlier studies have shown that B vitamins, such as folate and vitamin B6, can affect the metabolism of homocysteine, an amino acid that, at elevated levels, has been linked to adverse effects, including oxidative stress and damage to DNA, which can, in turn, influence carcinogenesis. However, no association with homocysteine and 8-OHdG was observed in the new study. Further study would be needed to determine whether or not smoking status or alcohol use status can modulate the relationships between vitamin B6 and oxidative DNA damage or carcinogenesis, the scientists noted.

1. Kuwahara K. et al. Serum vitamin B6, folate, and homocysteine concentrations and oxidative DNA damage in Japanese men and women. Nutrition. Published online June 2013.