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Prospective study of plasma folate, vitamin B12, and cognitive function and decline.
Epidemiology 2006; 17(6):650-7E

Abstract

BACKGROUND

The relation between B vitamins and cognitive decline is controversial. In this study, we explored the association of plasma folate and vitamin B12 with cognitive function measured approximately 10 years later.

METHODS

We determined plasma folate and vitamin B12 levels from blood samples collected in 1989 to 1990 and initially evaluated cognition in 1995 to 2001 among 635 women, age 70+ years, from the Nurses' Health Study. In a subset of 391, 3 repeated cognitive tests were completed for evaluation of cognitive decline over 4 years; repeated testing is ongoing for the remaining women. Our primary outcome was a global composite score of 6 neuropsychologic tests administered by telephone. We used linear regression models to estimate multivariable-adjusted mean cognitive performance across quartiles of the vitamins and longitudinal models for cognitive decline.

RESULTS

Higher vitamin levels were not associated with either initial cognitive performance or subsequent cognitive decline. Mean difference in initial global score for top versus bottom quartiles was 0.06 standard units for folate (95% confidence interval [CI] = -0.10 to 0.22) and 0.15 units for vitamin B12 (0.00 to 0.31). There were no dose-response trends for either nutrient. Women with high levels of both nutrients initially performed better than women low in both nutrients (global score, mean difference = 0.34; 95% CI = 0.05 to 0.62); this association did not hold for subsequent cognitive decline.

CONCLUSIONS

Combined B vitamin deficiency may be associated with impaired cognition, but in these healthy, well-nourished women, plasma folate and vitamin B12 were not related to cognitive function.

Authors+Show Affiliations

Department of Medicine, Channing Laboratory, Brigham and Women's Hospital, Boston, MA, USA. nhjhk@channing.harvard.eduNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural

Language

eng

PubMed ID

17028506

Citation

Kang, Jae Hee, et al. "Prospective Study of Plasma Folate, Vitamin B12, and Cognitive Function and Decline." Epidemiology (Cambridge, Mass.), vol. 17, no. 6, 2006, pp. 650-7.
Kang JH, Irizarry MC, Grodstein F. Prospective study of plasma folate, vitamin B12, and cognitive function and decline. Epidemiology. 2006;17(6):650-7.
Kang, J. H., Irizarry, M. C., & Grodstein, F. (2006). Prospective study of plasma folate, vitamin B12, and cognitive function and decline. Epidemiology (Cambridge, Mass.), 17(6), pp. 650-7.
Kang JH, Irizarry MC, Grodstein F. Prospective Study of Plasma Folate, Vitamin B12, and Cognitive Function and Decline. Epidemiology. 2006;17(6):650-7. PubMed PMID: 17028506.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Prospective study of plasma folate, vitamin B12, and cognitive function and decline. AU - Kang,Jae Hee, AU - Irizarry,Michael C, AU - Grodstein,Francine, PY - 2006/10/10/pubmed PY - 2007/1/12/medline PY - 2006/10/10/entrez SP - 650 EP - 7 JF - Epidemiology (Cambridge, Mass.) JO - Epidemiology VL - 17 IS - 6 N2 - BACKGROUND: The relation between B vitamins and cognitive decline is controversial. In this study, we explored the association of plasma folate and vitamin B12 with cognitive function measured approximately 10 years later. METHODS: We determined plasma folate and vitamin B12 levels from blood samples collected in 1989 to 1990 and initially evaluated cognition in 1995 to 2001 among 635 women, age 70+ years, from the Nurses' Health Study. In a subset of 391, 3 repeated cognitive tests were completed for evaluation of cognitive decline over 4 years; repeated testing is ongoing for the remaining women. Our primary outcome was a global composite score of 6 neuropsychologic tests administered by telephone. We used linear regression models to estimate multivariable-adjusted mean cognitive performance across quartiles of the vitamins and longitudinal models for cognitive decline. RESULTS: Higher vitamin levels were not associated with either initial cognitive performance or subsequent cognitive decline. Mean difference in initial global score for top versus bottom quartiles was 0.06 standard units for folate (95% confidence interval [CI] = -0.10 to 0.22) and 0.15 units for vitamin B12 (0.00 to 0.31). There were no dose-response trends for either nutrient. Women with high levels of both nutrients initially performed better than women low in both nutrients (global score, mean difference = 0.34; 95% CI = 0.05 to 0.62); this association did not hold for subsequent cognitive decline. CONCLUSIONS: Combined B vitamin deficiency may be associated with impaired cognition, but in these healthy, well-nourished women, plasma folate and vitamin B12 were not related to cognitive function. SN - 1044-3983 UR - https://www.unboundmedicine.com/medline/citation/17028506/Prospective_study_of_plasma_folate_vitamin_B12_and_cognitive_function_and_decline_ L2 - http://Insights.ovid.com/pubmed?pmid=17028506 DB - PRIME DP - Unbound Medicine ER -