Reduction of plasma homocysteine and serum methylmalonate concentrations in apparently healthy elderly subjects after treatment with folic acid, vitamin B12 and vitamin B6: a randomised trial

Abstract

Objectives: To investigate, in an elderly population: (1) the effects of oral B-vitamin therapy on P-tHcys, S-MMA and Hb/MCV, (2) the appropriate decision limit for 'high' metabolite concentrations and (3) the estimated prevalence of vitamin B 12 /folate deficiency on the basis of different decision limits. Design: Double-blind placebo-controlled intervention study. Setting: Outpatient clinic. Subjects: A total of 209 community-dwelling subjects, median age 76 y (range 70-93) y. Intervention: Four months of oral daily supplementation with 0.5 mg cyanocobalamin, 0.8 mg folic acid and 3 mg vitamin B 6 . Results: High P-tHcys was found in 64% of men and 45% of women, high S-MMA in 11% of both. Vitamin B 12 deficiency was observed in 7.2% and folate deficiency in 11% of all subjects. Health-related upper reference limits for the metabolites at the start were higher than the laboratory's upper reference limits. The latter were, however, similar to those of the vitamin replete group. There was a significant decrease in P-tHcys (Po0.001) and S-MMA (P ¼ 0.009) after 4 months of vitamin treatment. In a multivariate analysis, the P-Hcys change correlated positively with baseline P-tHcys and inversely with baseline P-folate and transferrin saturation (Fe/TIBC ratio). The S-MMA change correlated with baseline S-MMA and inversely with baseline vitamin B 12 and age. Conclusions: Suboptimal vitamin status is an important cause of elevated P-tHcys and S-MMA in apparently healthy elderly subjects. Oral B-vitamin therapy is an effective and convenient way to normalise P-tHcys and S-MMA. Sponsorship: SupportFRecip AB.

Holotranscobalamin is not influenced by decreased renal function in elderly men: the MrOS Sweden study

“…However, in the elderly, vitamin replete men have higher tHcy values than women, 33 pointing to the necessity of adequate vitamin measurements for the diagnosis of deficiency in the old age groups. Although our study, from a strict epidemiologic perspective might have some selection bias, we believe that the results are applicable to the elderly population.…”

“…17 For holoTC, we found a lower reference limit of 19.6 pmol/L, which is in accordance with the manufacturer's recommendations and some 13,25 but not other 32 studies, probably due to different populations studied. When calculating reference intervals we used exclusion criteria for the healthy subgroup partly based on our previous data, 33 and we used very strict criteria when excluding unhealthy individuals. For holoTC and total cobalamin, the lower reference limits did not markedly change after exclusion of 'non-healthy' subjects and they were in the same range as laboratory standards.…”

German Vegan Study: Diet, Life-Style Factors, and Cardiovascular Risk Profile

“…The lack of a signifi cant infl uence of cobalamin intake on serum concentrations in our study population may be due to the low variability of cobalamin intake and/or the alleged higher alimentary intake in the SV subgroup, which ingested cobalamin in form of enriched foods. Intervention studies show that an additional cobalamin intake can suffi ciently increase low serum concentrations and decrease elevated homocysteine concentrations [44] . Multiple linear regression analysis showed that cobalamin status and duration of adhering to the vegan diet were predictive for the homocysteine concentrations in our collective.…”

Clinical Utility of Genotyping the 677C>T Variant of Methylenetetrahydrofolate Reductase in Humans Is Decreased in the Post-Folic Acid Fortification Era

“…It has been shown that there is an inverse relationship between plasma B vitamin concentrations that are involved in the metabolism of homocysteine, especially folate, and plasma total homocysteine (tHcy) concentrations (8)(9)(10). In 1996, the U.S. FDA required that all enriched grain products be fortified with folic acid by January, 1998, to increase folate intake among childbearing-aged women and thus reduce the risk of neural-tube defects in newborns.…”