Subclinical micronutrient deficiencies in older adults are associated with chronic age-related diseases and adverse functional outcomes. In Germany, the elderly population is at risk of inadequate micronutrient intake, but representative studies of micronutrient status in old and very old adults are rare.
The aim of this study was to estimate the prevalence of subclinical vitamin D, folate, vitamin B12, and iron deficiency in older adults aged 65 to 93 years from the KORA-Age study in Augsburg, Germany (n = 1079), and to investigate the associated predictors using multiple logistic regression. Serum concentrations of 25-hydroxyvitamin D (25OHD), folate, vitamin B12, and iron were analyzed.
The prevalence of subclinical vitamin D and vitamin B12 deficiency was high, with 52.0% and 27.3% of individuals having low 25OHD (<50 nmol/L) and low vitamin B12 (<221 pmol/L) concentrations, respectively. In addition, 11.0% had low iron (men <11.6 µmol/L, women <9.0 µmol/L) and 8.7% had low folate (<13.6 nmol/L). Common predictors associated with subclinical micronutrient deficiency include very old age, physical inactivity, frailty, and no or irregular supplement use.
Subclinical micronutrient deficiency is a public health concern among KORA-aged participants, particularly for vitamin D and B12. Identified predictors provide further rationale for screening high-risk subgroups and developing targeted public health interventions to address prevalent micronutrient insufficiency among older adults.