Effects of High and Low Doses of Folic Acid on the Soluble Receptor Activator of Nuclear Factor-kappa B Ligand/Osteoprotegerin Ratio during Pregnancy.

BACKGROUND: Pregnancy Associated Osteoporosis (PAO) can lead to serious difficulties such as fragility fractures, elongated back pain and height loss in affected women. Soluble Receptor Activator of Nuclear Factor-Kappa B ligand (sRANKL) to Osteoprotegerin (OPG) ratio is chosen as a bone metabolism equation in many bone diseases characterized by bone resorption, such as post-menopausal osteoporosis and would be modified with folic acid supplementation. This study was done to compare the effects of high dose (5mg/day) and low dose (0.5 mg/day) folic acid in the RANKL/OPG ratio and Tumor Necrosis Factorα (TNFα) concentration during pregnancy. METHODS: Forty-five pregnant women who visited the AL-Zahra Hospital, Tabriz Iran, from September 2013 to November 2014 were assigned into two groups in this randomized, double-blind, clinical trial, included women who took 5 mg/day (group1) and who took 0.5 mg/day (Group 2) folic acid supplementation before pregnancy until 36th pregnancy. The biochemical variables in serum of pregnant women were measured before and at the end of the study. The study was registered in the Iranian Registry of Clinical Trials (IRCT) as ID, IRCT2013122315903N1. RESULTS: OPG levels were significantly higher compared with the baseline value (P=0.008), although sRANKL (P<0.001), TNFα (P=0.005) and sRANKL/OPG ratio (P<0.001) reduced significantly with high dose of folic acid supplementation. A significant positive correlation was observed between the decreased RANKL and TNFα levels (r=0.451, P=0.031) at the end of study in high dose group. CONCLUSION: High dose of folic acid supplementation could decrease bone resorptive biomarkers and may prevent PAO in pregnant women by increasing OPG and decreasing sRANKL and TNFα.

Effects of folic acid supplementation on serum homocysteine and lipoprotein (a) levels during pregnancy.

INTRODUCTION: There are many ideas concerning the etiology and pathogenesis of preeclampsia including endothelial dysfunction, inflammation and angiogenesis. Elevated levels of total homocysteine (Hcy) and lipoprotein (a) [Lp(a)] are risk factors for endothelial dysfunction. This study aimed to evaluate the effect of high dose folic acid (FA) on serum Hcy and Lp(a) concentrations with respect to methylenetetrahydrofolate reductase (MTHFR) polymorphisms 677C→T during pregnancy. METHODS: In a prospective uncontrolled intervention, 90 pregnant women received 5 mg FA supplementation before pregnancy till 36th week of pregnancy. The MTHFR polymorphisms 677C→T, serum lactate dehydrogenase activity, urine protein and creatinine concentrations were measured before starting folic acid administration. Serum levels of Hcy and Lp(a) were determined before and after completion of folic acid supplementation period. RESULTS: Supplementation of the patients with FA for 36 week decreased the median (minimum- maximum) levels of serum Hcy from 11.40 µmol/L (4.40-28.70) to 9.70 (1.60-20.80) µmol/L (p=0.001). There was no significant change in serum Lp(a) after FA supplementation (p=0.17). The overall prevalence of genotypes in pregnant women that were under study for MTHFR C677T polymorphism was 53.3% CC, 26.7% CT and 20.0% TT. There was no correlation between decreasing level of serum Hcy in the patients receiving FA and MTHFR polymorphisms. CONCLUSION: Although FA supplementation decreased serum levels of Hcy in different MTHFR genotypes, serum Lp(a) was not changed by FA supplements. Our data suggests that FA supplementation effects on serum Hcy is MTHFR genotype independent in pregnant women.