Researchers in Amsterdam found low levels of vitamin D among seniors who showed symptoms of depression.

A study of more than 1,200 elderly people between the ages of 65 and 95 showed that almost 40 per cent of the men and almost 57 per cent of the women had low vitamin D levels in their blood. These subjects were the most likely to show signs of minor or major depression.

The findings showed that blood vitamin D levels were 14 per cent lower in the subjects who had either minor or major depression, compared to the subjects who were not depressed.

The research was conducted by Dr. Witte J. G. Hoogendijk and colleagues from the Vrije Universiteit Medical Centre in the Netherlands and published in the May issue of the Archives of General Psychiatry.

The researchers say that further study needs to be conducted to find out if depression leads to low vitamin D levels because people are eating poorly or staying indoors and out of sunlight (a vitamin D source). However, it could also be that low vitamin D can cause depression.

Abstract:

Depression is Associated with Decreased 25-Hydroxyvitamin D and Increased Parathyroid Hormone Levels in Older Adults

Witte J. G. Hoogendijk, MD, PhD; Paul Lips, MD, PhD; Miranda G. Dik, PhD; Dorly J. H. Deeg, PhD; Aartjan T. F. Beekman, MD, PhD; Brenda W. J. H. Penninx, PhD

Context: Depression has incidentally been related to altered levels of 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH), but this relation has never been studied systematically.

Objective: To determine in a large population-based cohort whether there is an association between depression and altered 25(OH)D and PTH levels.

Design: Population-based cohort study (Longitudinal Aging Study Amsterdam).

Participants: One thousand two hundred eighty-two community residents aged 65 to 95 years.

Setting: The Netherlands.

Main Outcome Measure: Depression was measured using self-reports (Center for Epidemiologic Studies-Depression scale) and diagnostic interviews (Diagnostic Interview Schedule). Levels of 25(OH)D and PTH were assessed. Potentially confounding factors (ie, age, sex, smoking status, body mass index, number of chronic conditions, and serum creatinine concentration) and explanatory factors (ie, season of data acquisition, level of urbanization, and physical activity) were also measured.

Results: Levels of 25(OH)D were 14% lower in 169 persons with minor depression and 14% lower in 26 persons with major depressive disorder compared with levels in 1087 control individuals (P < .001). Levels of PTH were 5% and 33% higher, respectively (P = .003). Depression severity (Center for Epidemiologic Studies Depression Scale) was significantly associated with decreased serum 25(OH)D levels (P = .03) and increased serum PTH levels (P = .008).

Conclusion: The results of this large population-based study show an association of depression status and severity with decreased serum 25(OH)D levels and increased serum PTH levels in older individuals.

Link to Full Study (requires registration)