Depression is associated with decreased 25-hydroxyvitamin D and increased parathyroid hormone levels in older adults.
Hoogendijk WJ, Lips P, Dik MG, Deeg DJ, Beekman AT, Penninx BW.
Arch Gen Psychiatry. 2008 May;65(5):508-12.
PMID: 18458202
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.