Age-specific reference ranges are needed to interpret serum methylmalonic acid concentrations in the US population.
Am J Clin Nutr
; 110(1): 158-168, 2019 07 01.
Article
em En
| MEDLINE
| ID: mdl-31127807
ABSTRACT
BACKGROUND:
Serum vitamin B-12 is measured to evaluate vitamin B-12 status. Serum methylmalonic acid (MMA) is a specific functional indicator of vitamin B-12 status; however, concentrations increase with impaired renal function.OBJECTIVE:
The aim of this study was to describe the distribution of serum vitamin B-12 and MMA in US adults, and estimate age-specific reference intervals for serum MMA in a healthy subpopulation with replete vitamin B-12 status and normal renal function.METHODS:
We examined cross-sectional data for serum vitamin B-12 and MMA in adults participating in the NHANES from 2011 to 2014. Vitamin B-12 was measured by electrochemiluminescence assay and MMA by isotope-dilution liquid chromatography-tandem mass spectrometry.RESULTS:
In both bivariate and multivariate analyses, age, race/Hispanic origin, and vitamin B-12 supplement use were generally significantly associated with serum vitamin B-12 and MMA concentrations. Serum MMA concentrations increased with age, particularly in persons aged ≥70 y. Non-Hispanic white persons had lower vitamin B-12 and higher MMA concentrations than non-Hispanic black persons. Shorter fasting times and impaired renal function were significantly associated with higher serum MMA concentrations, but not with serum vitamin B-12 concentrations after controlling for covariates. The central 95% reference intervals for serum vitamin B-12 and MMA concentrations were widest for persons aged ≥70 y compared with younger age groups. Compared with the overall population, the central 95% reference intervals for serum MMA concentrations were considerably narrower for a vitamin B-12-replete subpopulation with normal renal function, but still age-dependent. Serum vitamin B-12 showed little, whereas serum MMA showed notable, increases with impaired renal function.CONCLUSIONS:
The higher serum MMA concentrations throughout the entire distribution in older persons (especially persons aged ≥70 y) who are vitamin B-12-replete and have normal renal function indicate the need for age-specific MMA reference intervals to better interpret vitamin B-12 status in epidemiologic research.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vitamina B 12
/
Deficiência de Vitamina B 12
/
Fatores Etários
/
Ácido Metilmalônico
Tipo de estudo:
Diagnostic_studies
Limite:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Am J Clin Nutr
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Gabão