One in two persons aged 65 and above has sub-optimal levels of vitamin D in the blood. This is the conclusion of an investigation conducted by researchers at the Helmholtz Zentrum München, as part of the population-based KORA-Age study in the region of Augsburg. Moreover, the authors of the study report, one in four older adults has sub-optimal vitamin B12 levels.
Since more than 30 years, the KORA Cooperative Health Research platform has been examining the health of thousands of people living in the greater Augsburg area in Southern Germany. The aim of the study is to understand the impact of environmental factors, lifestyle factors and genes on health. “In this context, we were also interested in examining the micro-nutrient status of older adults, including vitamins” explains study leader Dr Barbara Thorand of the Institute of Epidemiology (EPI), Helmholtz Zentrum München. “So far, in Germany, research data on this topic has been relatively thin on the ground.”
Overall, the scientists examined blood samples of 1,079 older adults, aged 65 to 93 years from the KORA study. Their analysis focused on levels of four micro-nutrients: vitamin D, folate, vitamin B12 and iron.
“The results are very clear,” explains first author Romy Conzade. “52% of the examined older adults had vitamin D levels below 50 nmol/L and thus had a sub-optimal vitamin D status.”
The scientists also observed shortages with regard to some of the other micronutrients. Notably, 27% of older adults had vitamin B12 levels below the cut-off. Moreover, in 11% of older adults, iron levels were too low, and almost 9% did not have enough folate in their blood.
EPI director Professor Annette Peters puts the data into context: “By means of blood analyses, the current study has confirmed the critical results of the last German National Nutrition Survey (NVS II), which revealed an insufficient intake of micro-nutrients from foods. This is a highly relevant issue, particularly in light of our growing aging population.”
The majority of older adults with sub-optimal vitamin levels had in common that they were very old, physically inactive or frail. Special attention should, therefore, be paid to these groups with a higher risk for micro-nutrient deficiencies, explain the researchers.
“Our study also shows that regular intake of vitamin-containing supplements goes along with improved levels of the respective vitamins,” says Thorand. “However, vitamin-containing supplements are not a universal remedy, and particularly older people should watch out for maintaining a healthy and nutritious diet.”
In this context, the authors say their next objective is to continue investigating the metabolic pathways that link supplement intake, micro-nutrient status and disease states.
Subclinical micronutrient deficiency in older adults is associated with chronic age-related diseases and adverse functional outcomes. In Germany, the older population is at risk of insufficient micronutrient intake, but representative studies on micronutrient status in old and very old adults are scarce. This study’s objectives were to estimate the prevalence of subclinical vitamin D, folate, vitamin B12 and iron deficiencies among older adults, aged 65 to 93, from the KORA-Age study in Augsburg, Germany (n = 1079), and to examine 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 deficiencies were high, with 52.0% and 27.3% of individuals having low 25OHD (<50 nmol/L) and low vitamin B12 concentrations (<221 pmol/L), respectively. Furthermore, 11.0% had low iron (men <11.6 µmol/L, women <9.0 µmol/L) and 8.7% had low folate levels (<13.6 nmol/L). Common predictors associated with subclinical micronutrient deficiency included very old age, physical inactivity, frailty and no/irregular use of supplements. Subclinical micronutrient deficiency is a public health concern among KORA-Age participants, especially for vitamins D and B12. The predictors identified provide further rationale for screening high-risk subgroups and developing targeted public health interventions to tackle prevailing micronutrient inadequacies among older adults.
Romy Conzade, Wolfgang Koenig, Margit Heier, Andrea Schneider, Eva Grill, Annette Peters, Barbara Thorand