Effects of folic acid supplementation on serum folate and plasma homocysteine concentrations in older adults: a dose-response trial.

Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21287, USA.
American journal of epidemiology (Impact Factor: 4.98). 10/2010; 172(8):932-41. DOI: 10.1093/aje/kwq197
Source: PubMed

ABSTRACT The authors' objective in this study was to estimate the changes in serum folate and homocysteine concentration that resulted from 6 weeks of supplementation with folic acid. A randomized, double-blind, placebo-controlled, dose-response trial with a parallel-group design was conducted. A total of 133 participants aged 60-90 years (70% female, 19% nonwhite) were assigned to receive 0, 100, 400, 1,000, or 2,000 μg/day of folic acid for 6 weeks. Data were collected in the United States between June and September 1996. At baseline, median serum folate and plasma homocysteine concentrations were 5.7 ng/mL (interquartile range (25th-75th percentiles), 4.1-7.8) and 8.3 μmol/L (interquartile range, 7.1-10.0), respectively. As the folic acid dose increased, serum folate levels increased (P-trend < 0.001). There was no dose-response relation with homocysteine level among all participants. In analyses restricted to persons with the lowest serum folate concentration (<4.5 ng/mL) at baseline, there was a trend (P = 0.06) toward decreased homocysteine levels with increasing folic acid dose. In healthy, older adults with adequate folate status, folic acid supplementation is not beneficial for homocysteine reduction. However, for older adults with low serum folate levels, supplementation will improve folate status and may be beneficial for lowering homocysteine concentrations.

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    ABSTRACT: Background In spite of several studies, the impact of homocysteine level and folic acid supplementation on bone metabolism is yet to be recognized. In this registered clinical trial (IRCT2014042217385N1), we aimed to find out the power of 6-month folic acid supplementation on homocysteine level and bone metabolism.Methods Forty postmenopausal osteoporotic women (50 to 87 years) were enrolled in the study. All participants were randomized to receive folic acid 1 mg (n¿=¿17) or placebo (n¿=¿14). At baseline, 3 months, and finally 6 months post intervention, the level of homocysteine, vitamin B12, and bone biomarkers were measured.ResultsBoth groups were similar at baseline. The homocysteine decreased in both groups but statistically non-significant (P¿>¿0.05). The changes of the serum level of vitamin B12, osteocalcin, and ß cross laps were significant between groups after 6 months (P¿¿¿0.05).Conclusion The trend of changes of bone biomarkers after 6 months folic acid supplementation shows that homocysteine concentration and/or folic acid supplementation have impact on the rate of bone metabolism. However, further investigations by larger sample size and differentiating age and gender are still needed to clarify the exact role of folate, homocysteine and vitamin B12.
    DARU Journal of Pharmaceutical Sciences 09/2014; 22(1):62. DOI:10.1186/s40199-014-0062-9 · 1.11 Impact Factor
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    ABSTRACT: Purpose: We assessed associations between serum levels of homocysteine, vitamin B12 and folate and the prevalence and 5-year incidence of posterior subcapsular (PSC) cataract in Blue Mountains Eye Study participants. Methods: We examined 3508 participants aged 49+ years during 1997-2000, including 2335 (75.1% of survivors) original and 1174 (85.2% of those eligible) newly recruited subjects. Five years later (2002-2004), 1952 (76.6% of survivors) original participants were re-examined. Detailed examinations, including lens photographs and fasting blood tests, were conducted at both visits. Logistic regression models estimated odds ratios (OR) and 95% confidence intervals (CI) after multivariable adjustment. Results: In this population, those with PSC were older, less likely to have higher education and more likely to have diabetes and myopia. PSC prevalence was 5.7% (150/2644). Higher levels of homocysteine (per standard deviation (SD), OR 1.17, 95% CI 1.00-1.37,) and lower levels of folate (per SD, OR 1.24, 95% CI 0.99-1.56) were associated with prevalent PSC. There was significant interaction (p<0.05) between vitamin B12 and homocysteine; for B12 ≥125pmol/l, 28% higher PSC prevalence was associated with homocysteine (per SD, OR 1.28, 95% CI 1.09-1.52), however, for B12 <125pmol/l, non-significant lower PSC prevalence was associated with homocysteine (per SD, OR 0.16, 95% CI 0.02-1.57). 5-year PSC incidence was 5.7% (n=59/1030) with no significant associations with homocysteine, B12 and folate. Conclusions: Higher serum homocysteine level was associated with PSC cataract prevalence in this population. Vitamin B12 status seemed to modify this association. Lack of longitudinal association could have resulted from insufficient study power. Copyright © 2014 by Association for Research in Vision and Ophthalmology.
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    ABSTRACT: Introduction: The use of alternative therapies for the treatment of menopausal hot flashes has increased due to the serious risk of hormone therapy. Most alternative therapies have not been accepted by women. Therefore, conducting a study to find effective treatment, which has a low rate of complications and is more acceptable, is necessary. The aim of this study was to assess the effects of folic acid on menopausal hot flashes. Methods: In the present study 70 menopausal women were placed into two groups of 35 with random allocation, and were treated with folic acid 1 mg tablets and placebo tablets once a day during four weeks. Information was gathered by questionnaire, interviews, and hot flash diary during five stages. Comparisons of within-group Results were performed by ANOVA and between-group results were performed using ANCOVA. Data were analyzed by SPSS for Windows. Results: There was a significant difference between mean severity, duration, and frequency of hot flashes before and after treatment within both groups. In comparing the results between the groups, mean hot flash severity in second, third, and fourth weeks were significantly different. The mean hot flash frequency was significantly different in third and fourth weeks, and the mean hot flash duration was significantly different in the fourth week. Conclusion: The results of the present study indicated that folic acid was effective in reducing the severity, duration, and frequency of hot flashes during menopause. Therefore, it can be recommended as an affordable and accessible method for treating menopausal hot flash for women.
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