Effect of zinc supplementation on circulating concentrations of homocysteine, vitamin B12, and folate in a postmenopausal population

Abstract

Introduction: The decrease in estrogen levels associated with menopause increases the risk of deficiencies of key micronutrients such as zinc and of disturbances in methylation cycle-related markers. The present study assesses the effect of 8-week Zn supplementation upon circulating concentrations of Hcy, B12, and Fol levels in a population of postmenopausal women. Methods: Fifty-one postmenopausal women aged between 44 and 76 years took part in the study. Two randomized groups (placebo and zinc [50 mg/day]) were treated during 8 weeks. Nutrient intake was assessed based on the 72-hour recall method. Zinc was analyzed by flame atomic absorption spectrophotometry. Clinicalnutritional parameters were determined by enzyme immunoassay techniques. Results: Folate levels increased significantly (p < 0.05) in the zinc group on comparing the baseline versus followup values. Homocysteine decreased in the inter-group analysis (p < 0.05) after the intervention. Furthermore, higher folate (r = - 0.632; p = 0.005) and vitamin B12 (r = - 0.512; p = 0.030) levels were correlated to low homocysteine levels in the zinc group after the intervention, although the zinc intervention had the same effect on B12 levels in both groups. Conclusion: Zinc supplementation enhanced circulating folate and homocysteine by improving the folate values in the zinc-supplemented group and decreasing homocysteine levels inter-groups. Further studies involving larger samples and optimizing the doses and intervention period are needed to reinforce our main findings.