The effect of dietary protein on the metabolism of vitamin B-6 in humans

A study assessed the effect of dietary protein on vitamin B6 status in 8 men (ages 21-31) receiving a minimal (but adequate) and constant (1.6 mg/day) level of vitamin B6 while on a low, medium, or high protein diet. Urinary and plasma vitamin B6 levels correlated negatively with protein intake, suggesting that increased dietary protein levels are associated with vitamin B6 retention for increased amino acid catabolism. The results point out the need to evaluate protein intake when vitamin B6 requirement or status in humans is assessed.(wz)