Priscille G Massé, J Dennis Mahuren, Carole Tranchant, Juliana Dosy – The American Journal of Clinical Nutrition, Published: 01 October 2004
ABSTRACT
Background: Although many studies have reported reduced vitamin B-6 status with aging, little information is available about the specific effects of menopause.
Objective: We aimed to examine vitamin B-6 metabolism in premenopausal and early postmenopausal women.
Design: We examined dietary intake and vitamin B-6 metabolites in the plasma, erythrocytes, and urine of 30 premenopausal women (x̄ ± SD age: 41.9 ± 4.8 y) and 30 women (aged 54.0 ± 3.8 y) who were 4.0 ± 1.4 y past menopause.
Results: Vitamin B-6 intake in the postmenopausal group (1.97 ± 0.40 mg/d) was significantly greater than that in the premenopausal group (1.63 ± 0.50 mg/d). Plasma pyridoxal phosphate (PLP) and pyridoxal concentrations and erythrocyte PLP, pyridoxal, and pyridoxamine phosphate concentrations were in the normal range in both groups and did not differ significantly between the 2 groups. Plasma and erythrocyte 4-pyridoxic acid (4-PA) concentrations were significantly higher in the postmenopausal group than in the premenopausal group, which may have been due at least partly to the slightly higher vitamin B-6 intake of the former group. Erythrocyte 4-PA was correlated (r = −0.37, P < 0.01) with serum estradiol in both groups. Urinary 4-PA did not differ significantly between the 2 groups. The serum phosphate concentration was higher in the postmenopausal group than in the premenopausal group, and it was correlated (r = 0.40, P < 0.01) with plasma PLP. Inhibition of alkaline phosphatase by the increased phosphate may help to increase plasma PLP.
Conclusion: Menopause may not necessarily be associated with a decrease in vitamin B-6 status.