Folate and vitamin B12 status: temporal evaluation after mandatory fortification in Brazil.

OBJECTIVES: To perform temporal evaluation of folate and vitamin B12 status and their associated factors in a Brazilian population exposed to mandatory fortification. METHODS: Data from the cross-sectional population-based studies 2008 and 2015 Health Surveys of São Paulo, including individuals ≥ 20 years, both sexes, N = 549 in 2008 and N = 610 in 2015. Folate and vitamin B12 biomarkers status, B-complex supplements and medications use, and dietary intake were assessed. RESULTS: Serum folate concentrations increased in the entire population, adults and older adults in 2015 compared to 2008, while serum vitamin B12 concentration increased only in older adults. B-complex supplement use raised in 2015, reflecting in serum vitamins status. Overall serum vitamin B12 deficiencies (<200 pg/mL) were 23.2% and 21.2%, while serum folate deficiencies (<4 ng/mL) were 4.1% and 1.5% in 2008 and 2015, respectively. The lowest quintile of serum folate (≤8.7 ng/mL) was positively associated with smoking and oral contraceptive use, while the highest quintile (≥17.8 ng/mL) was inversely associated with smoking and positively with B-complex supplement use. The odds of having vitamin B12 deficiency was inversely associated with B-complex supplement use, higher serum folate median, higher dietary vitamin B12 intake and positively associated with using oral contraceptive. CONCLUSION: Overall deficiency of folate has decreased in 2015, being almost non-existent. Low vitamin B12 status presented similar proportions in the overall population comparing both periods, except for older adults. Different predictive variables were identified to better understand vitamins status outcomes in the most recent period of the study.

Magnesium status and the physical performance of volleyball players: effects of magnesium supplementation.

The aim of this study was to test the hypothesis that magnesium supplementation influences the physical performance of volleyball players, as the efficacy of this approach remains questionable. Twenty-five professional male volleyball players were assigned randomly to experimental (350 mg Mg · d(-1), 4 weeks) and control groups (500 mg maltodextrin · d(-1), 4 weeks) maintaining inter-group homogeneity of urinary magnesium. Erythrocyte, plasma and urinary magnesium levels, plasma creatine kinase activity, lactate production, maximal oxygen uptake (VO2 max) and plyometric (squat jump, countermovement jump, countermovement jump with arm swing) and isokinetic (peak torque, potency and total work) performances were evaluated before (T0) and after (T1) supplementation. Levels of erythrocyte and urinary magnesium and creatine kinase activity and VO2 max remained within normal ranges in both groups. Plasma magnesium decreased significantly only within the experimental group. Significant decreases in lactate production and significant increases (of up to 3 cm) in countermovement jump and countermovement jump with arm swing values were detected in the experimental group following magnesium supplementation, but not in the control group at T1. It is concluded that magnesium supplementation improved alactic anaerobic metabolism, even though the players were not magnesium-deficient.

Magnesium and diabetes mellitus: their relation.

The aim of this review was to elaborate a synthesis about the discussions on magnesium and diabetes mellitus, in the last 14 years. The magnesium deficiency has been associated with chronic diseases, amongst them, diabetes mellitus. Epidemiological studies had shown low levels of magnesium ingestion in the general population, as well as a relation between the ingestion of food rich in magnesium and the reduction of diabetes installation and its complications. Hypomagnesemia is frequently present in diabetic patients, however there is not an exact elucidation of the mechanism of magnesium deficiency in diabetes mellitus. On the other hand, in the presence of this illness, it is observed that inadequate metabolic control can affect the corporal concentrations of magnesium, developing hypomagnesemia, which may be still directly related with some micro and macrovascular complications observed in diabetes, as cardiovascular disease, retinopathy and neuropathy. This way, the chronic complications of diabetes can appear precociously. Based on this, the supplementation with magnesium has been suggested in patients with diabetes mellitus who have proven hypomagnesemia and the presence of its complications.