Recently, studies on the role of certain micronutrients in genome stability have gathered a series of evidences for their impact on DNA synthesis, replication or on DNA repair mechanisms (1).
Today, the magnitude of DNA damages due to micronutrient deficiencies is estimated to be of the same range of order than those due to UV radiations.
Last June, a Japanese group published a study linking vitamin B6 supplementation with reduced DNA oxidative damage (2). The results of data analyzed from 293 men and 207 women aged between 21 and 66 showed that pyridoxal (one of the 7 forms of vitamin B6) was associated with a lower level of a marker for oxidative stress in men, but not in women. Moreover, that association was limited to non-smokers and men who did not drink a lot of alcohol.
The active form of vitamin B6 (pyridoxal-5-phosphate or PLP) is known to be involved in numerous processes of amino acids and protein metabolism. It plays a crucial role in the synthesis of some antibodies and neurotransmitters, histamine and hemoglobin, as well as in gene expression. It is also required in the production of vitamin B3, or niacin. As it can neither be produced nor stored by the human body, vitamin B6 has to be taken up from dietary sources, which include meat, fish, whole grain products, vegetables, nuts and bananas.
This antioxidative action of vitamin B6 is well in line with previous studies that have linked vitamin B6-deficiency with impaired antioxidative defenses in rats and with decreased synthesis rates of the antioxidant glutathione in humans (3, 4).
Another study conducted in one hundred obese diabetic Emirati subjects showed that supplementation with antioxidant and B-group vitamins improved antioxidant status and reduced tissue inflammation, and thus may have an anti-inflammatory effect in obese diabetic patients (5).
Further studies are now required to confirm whether and how increasing vitamin B6 levels can protect against oxidative DNA damage.
1. Bull C and Fenech M (2008) Genome-health nutrigenomics and nutrigenetics: nutritional requirements or ‘nutriomes’ for chromosomal stability and telomere maintenance at the individual level. Proc Nutr Soc 67: 146-56 2. Kuwahara K, Nanri A, Pham NM, Kurotani K, Kume A, Sato M, Kawai K, Kasai H and Mizoue T (2013) Serum vitamin B, folate, and homocysteine concentrations and oxidative DNA damage in Japanese men and women. Nutrition 3. Lamers Y, O’Rourke B, Gilbert LR, Keeling C, Matthews DE, Stacpoole PW and Gregory JF, 3rd (2009) Vitamin B-6 restriction tends to reduce the red blood cell glutathione synthesis rate without affecting red blood cell or plasma glutathione concentrations in healthy men and women. Am J Clin Nutr 90: 336-43 4. Cabrini L, Bergami R, Fiorentini D, Marchetti M, Landi L and Tolomelli B (1998) Vitamin B6 deficiency affects antioxidant defences in rat liver and heart. Biochem Mol Biol Int 46: 689-97 5. Gariballa S, Afandi B, Abuhaltem M, Yassin J, Habib H and Ibrahim W (2013) Oxidative damage and inflammation in obese diabetic Emirati subjects supplemented with antioxidants and B-vitamins: a randomized placebo-controlled trail. Nutr Metab (Lond) 10: 21