Subjective well-being in older adults: folate and vitamin B12 independently predict positive affect

Br J Nutr. 2015 Oct 28;114(8):1321-8. doi: 10.1017/S0007114515002949. Epub 2015 Sep 8.


Vitamin B12, folate and homocysteine have long been implicated in mental illness, and growing evidence suggests that they may play a role in positive mental health. Elucidation of these relationships is confounded due to the dependence of homocysteine on available levels of vitamin B12 and folate. Cross-sectional and longitudinal relationships between vitamin B12, folate, homocysteine and subjective well-being were assessed in a sample of 391 older, community-living adults without clinically diagnosed depression. Levels of vitamin B12, but not folate, influenced homocysteine levels 18 months later. Vitamin B12, folate and their interaction significantly predicted levels of positive affect (PA) 18 months later, but had no impact on the levels of negative affect or life satisfaction. Cross-sectional relationships between homocysteine and PA were completely attenuated in the longitudinal analyses, suggesting that the cross-sectional relationship is driven by the dependence of homocysteine on vitamin B12 and folate. This is the first study to offer some evidence of a causal link between levels of folate and vitamin B12 on PA in a large, non-clinical population.

Keywords: CFI comparative fit index LS life satisfaction; Folate; Homocysteine; NA negative affect; PA positive affect; Positive affect; SWB subjective well-being; Subjective well-being; Vitamin B12.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Affect*
  • Aged
  • Aged, 80 and over
  • Body Mass Index
  • Cross-Sectional Studies
  • Energy Intake
  • Energy Metabolism
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-3 / blood
  • Female
  • Folic Acid / blood*
  • Homocysteine / blood*
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Socioeconomic Factors
  • Vitamin B 12 / blood*


  • Fatty Acids, Omega-3
  • Homocysteine
  • Folic Acid
  • Vitamin B 12