The Effect of Vitamin B and Folic Acid Supplementation on Plasma Homocystiene Levels in Women with Polycystic Ovary Syndrome Treated with Metformin. A Randomized Controlled Trial

Research Article

Austin J Reprod Med Infertil. 2015;2(2): 1013.

The Effect of Vitamin B and Folic Acid Supplementation on Plasma Homocystiene Levels in Women with Polycystic Ovary Syndrome Treated with Metformin. A Randomized Controlled Trial

Iman Abdel Mohsen Khalil*

The Department of Obstetrics & Gynaecology, Faculty of Medicine, Cairo University, Kasr Al Aini Hospital, Egypt

*Corresponding author: Iman Abdel Mohsen Khalil, The Department of Obstetrics & Gynaecology, Faculty of Medicine, Cairo University, Kasr Al Aini Hospital, Egypt

Received: April 22, 2015; Accepted: June 27, 2015; Published: June 30, 2015


Objective: To assess the effect of vitamin B-group and folic acid supplementation on serum levels of homocysteine (Hcy) in patients with polycystic ovarian syndrome (PCOS) on short term metformin treatment.

Design: Randomized controlled study.

Methods: PCOS patients were randomly assigned to two groups. Group 1 (n =40) received metformin only (500mg 3 times daily); group 2 (n=40) received metformin (500mg 3 times daily) plus vitamin B-group (twice daily) and folic acid (once daily) for 16 weeks. In groups, plasma Hcy, vitamin B12, folic acid, lipid profile, and HOMA test were recorded at baseline and after 16 weeks.

Results: There were no statistically significant differences with respect to background and hormonal characteristics of the two groups. An 18% increase in Hcy levels was seen after 16 weeks of metformin therapy, while 23% decrease in Hcy levels was detected when B-group vitamin and folic acid were added to metformin. There was a 14.3% decrease in vitamin B12 levels and 5.8% in folic acid levels in Group 1.

Conclusions: Vitamin B-group and folic acid supplementation to PCOS women treated with metformin is essential when one considers the elevated levels of Hcy and the possible increasing effect of metformin on Hcy levels in patients with PCOS.

Keywords: Vitamin B; Homocysteine; Metformin; Polycystic ovarian syndrome


Homocysteine (Hcy) is an intermediate formed amino acid during the breakdown of the amino acid methionine. Hyperhomocysteinaemia is an accepted risk factor for premature cardiovascular disease (CVD) and stroke risk in healthy populations [1-3]. Experimental studies have demonstrated that high plasma concentrations of Hcy have been shown to correlate with blood pressure [4], body mass index and insulin resistance [5, 6].

Apart from the well established positive association between Hcy and risk of cardiovascular disease, elevated levels of Hcy in pregnant women have been linked to increased risk of preeclampsia, abruption of the placenta intrauterine growth restriction, and early pregnancy loss [7].

Polycystic ovary syndrome (PCOS) is the most common endocrine disease in women of reproductive age and is estimated to affect 5-10 % of the population [8]. PCOS is not only the most common reproductive disorder but also a plurimetabolic syndrome [9]. Obesity, insulin resistance and resultant hyperinsulinemia are cardinal features of PCOS with a greater risk of developing diabetes mellitus, hypertension and dyslipidemia [10].

Higher serum Hcy concentrations have been found in women with PCOS compared with controls by several authors [11-13], while others have found no association between PCOS and Hcy [14,15].

All current data suggest that PCOS possesses the intrinsic conditions that lead to an increased incidence of factors predisposing to cardiovascular diseases [16-18].

Recognition of insulin resistance as a principal factor in the pathogenesis of PCOS has led to the use of insulin sensitizers for its treatment [19]. The most extensively studied insulin sensitizer is metformin-an oral antihyperglycaemic agent used initially in the treatment of type 2 diabetes mellitus. It has been shown that metformin increases total serum Hcy levels in PCOS women [20] as well as it reduces levels of vitamin B12 and folic acid, which results in a modest increase in Hcy levels [21].

In view of these considerations, this study was designed to evaluate the effect of vitamin B and folic acid supplementation on plasma Hcy concentrations in women with PCOS treated with metformin.

Material and Methods

Eighty women with PCOS participated in this randomized controlled study. Institutional review board approval was attained before beginning the trial. PCOS women were recruited from the gynaecology & dermatology clinics of Cairo University Hospital during the period from September 2010 to October 2011. Most of the women were complaining from infertility and minority were unmarried complaining from hirsutism, acne and/or oligomenorrhea or amenorrhea. Informed written consent was obtained from all participants after explanation of the nature and purpose of the study. PCOS was defined when at least two of the following three features were present after the exclusion of other etiologies: oligomenorrhea or amenorrhea, signs of hyperandrogenism (e.g. hirsutism, acne and alopecia) or elevated levels of total or free testosterone, and polycystic ovaries on ultrasonography according to the Rotterdam criteria [22]. All women had normal thyroid, renal and hepatic functions. Their prolactin levels were within normal limits. Exclusion criteria were as follow; pregnancy, current or within previous 6 months use of oral contraceptives, vitamins, antiandrogens, anti-diabetics, statins, glucocorticoids or other hormonal drugs, cigarette smoking, chronic alcohol consumption, coffee consumption more than 2 cups/day, blood pressure of ≥ 130/85 mmHg or treated hypertension, known CVD and diabetes mellitus. During the testing period, all participants were asked to keep their normal diet and not perform any sporting activity.

Patients were randomly assigned by a research nurse into two groups the randomization was completed by opening sealed envelopes containing random numbers generated by computer. Group 1(n=40) received metformin (500 mg 3 times daily) (Glucophage; MerckSerono); group 2 (n =40) received metformin (500 mg 3 times daily) and vitamin B (Neurobion ;Merck) [vitamin B1 (100 mg); vitamin B6 (200 mg); vitamin B12 (200mcg) twice daily plus folic acid 500 mcg (Folic acid-Mepaco; Egypt) for 16 weeks.

All women were examined clinically. Weight, height, body mass index (BMI) and waist/hip ratio (WHR) were recorded. Baseline day 3 FSH, LH, E2 and total testosterone were measured in spontaneous or progestogen-induced menses with specific chemiluminescence assays from the Abbott Architect system (Chicago, USA). The plasma glucose and insulin were measured after 12 hours fasting. Plasma glucose levels were measured using the glucose oxidase method; plasma insulin concentrations were measured by the micro-particle enzyme immunoassay method (AxSYM insulin assay; Abbott, Japan). The lipid profile was measured using an Abbott-Aeroset (Chicago, IL, USA) auto analyser with original kits after an overnight fast.

Homocysteine was measured as total homocysteine from plasma separated and frozen immediately after venipuncture; the plasma homoysteine concentration was measured by chemiluinescent enzyme immunoassay (Immulite 2000 Diagnosic Products, LA, and CA). Plasma folic acid and vitamin B12 concentrations were measured using the chemiluminescent method with an E170 immunoassay analyser (Roche Diagnostics Corp., USA).

Insulin resistance (IR) was determined by fasting insulin, the glucose: insulin ratio [glucose (mmol/l)/insulin (mIU/l)], the HOMA (homeostasis model assessment) index [glucose (mmol/l)*insulin (mIU/l)/22.5], [23] and quantitative insulin sensitivity check index (QUICKI) which is derived by calculating the inverse of sum of logarithmically expressed values of fasting insulin and glucose [24].

Plasma Hcy, vitamin B12, folic acid, lipid profile, and HOMA tests were recorded at baseline and after 16 weeks. Safety measures included clinical assessment for adverse events and monitoring of complete blood count and renal and liver function tests.

Statistical Analysis

Data were statistically described in terms of mean ± standard deviation (±SD). Comparison of numerical variables between the study groups was done using Student t test for independent samples. Within group comparison between before and after treatment was done using paired t test. A p values less than 0.05 was considered statistically significant. All statistical calculations were done using computer programs SPSS (Statistical Package for the Social Science; SPSS Inc., Chicago, IL, USA) version 15 for Microsoft Windows.


Eighty patients were included and 65 patients completed the study; 33 patients in the group 1, and 32 patients in group 2 (Figure 1). Nine patients became pregnant (4 in group 1 and 5 in group 2). Five patients withdrew because of gastrointestinal adverse effects of metformin (3 in group 1 and 2 in group 2). One patient withdrew from the study owing to lack of motivation in group 2. There were no statistically significant differences in baseline age, BMI, duration of infertility, waist: hip ratio, FSH, LH, E2, total testosterone, Hcy concentrations, vitamin B12 , folic acid ,lipid profile and insulin sensitivity markers between the two groups (Table I).