Significant correlations of plasma homocysteine and serum methylmalonic acid with movement and cognitive performance in elderly subjects but no improvement from short-term vitamin therapy: a placebo-controlled randomized study

• Published in: The American journal of clinical nutrition 2005-05, Vol.81 (5), p.1155-1162
• Main Authors: Lewerin, C, Matousek, M, Steen, G, Johansson, B, Steen, B, Nilsson-Ehle, H
• Format: Article
• Language: English
• Subjects: Acids; Aged; Biological and medical sciences; blood serum; cognition; Cognition & reasoning; Cognition - drug effects; Dietary supplements; Double-Blind Method; elderly; elderly nutrition; Feeding. Feeding behavior; Female; folic acid; Folic Acid - therapeutic use; Folic Acid Deficiency - drug therapy; functional status; Fundamental and applied biological sciences. Psychology; Geriatrics; homocysteine; Homocysteine - blood; Humans; Locomotion - drug effects; Male; methylmalonic acid; Methylmalonic Acid - blood; nutritional status; Older people; physical activity; Plasma; Psychomotor Performance - drug effects; pyridoxine; Short term; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vitamin B; Vitamin B 12 Deficiency - drug therapy; Vitamin B 6 Deficiency - drug therapy; Vitamin B Complex - therapeutic use; vitamin B12; vitamin deficiencies; vitamin supplements; Vitamins
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/81.5.1155

Background: Deficiencies of vitamin B-12, folic acid, and vitamin B-6-as defined by laboratory measures-occur in 10-20% of elderly subjects. The clinical significance remains unresolved. Objective: The objective was to explore any association between vitamin status and vitamin treatment and movement and cognitive performance in elderly subjects. Design: Community-dwelling subjects (n = 209) with a median age of 76 y were randomly assigned to daily oral treatment with 0.5 mg cyanocobalamin, 0.8 mg folic acid, and 3 mg vitamin B-6 or placebo (double blind) for 4 mo. Movement and cognitive performance tests were performed before and after treatment. Results: A high plasma total homocysteine (tHcy) concentration (greater than or equal to 16 micromol/L) was found in 64% of men and in 45% of women, and a high serum methylmalonic acid (MMA) concentration (greater than or equal to 0.34 micromol/L) was found in 11% of both sexes. Movement time, digit symbol, and block design (adjusted for age, sex, smoking, and creatinine) correlated independently with plasma tHcy (P < 0.01, < 0.05, and < 0.01, respectively); the simultaneity index and block design correlated with serum MMA (P < 0.05 for both). Vitamin therapy significantly decreased plasma tHcy (32%) and serum MMA (14%). No improvements were found in the movement or cognitive tests compared with placebo. Neither vitamin therapy nor changes in plasma tHcy, serum MMA, serum vitamin B-12, plasma folate, or whole-blood folate correlated with changes in movement or cognitive performance. Conclusions: High plasma tHcy and serum MMA were prevalent and correlated inversely with movement and cognitive performance. Oral B vitamin treatment normalized plasma tHcy and serum MMA concentrations but did not affect movement or cognitive performance. This might have been due to irreversible or vitamin-independent neurocognitive decline or to an insufficient dose or duration of vitamins.