Effects of vitamin d supplementation on well-being, postural control, muscle strength, bone and calcitropic hormones – a randomized doubleblind placebo controlled trial

Background: Antidepressants may increase the risk of fractures through negative effects on the musculoskeletal system that could be hindered by vitamin D supplements. Objectives: To study the pleiotropic effects of daily vitamin D supplementation in depressed patients treated with citalopram (patients) and healthy controls. Design: Randomised double blind placebo controlled trial. Setting: A study of Danish women in the age 50 to 90 years. Participants: A total of 21 patients and 50 controls. Intervention: Participants received daily vitamin D supplementation (50 micrograms) or placebo in one year. Measurements: Bone Densitometry by dual-energy x-ray absorptiometry. Serum 25-hydroxyvitamin D, intact-Parathyroid Hormone, type 1 procollagen N terminal peptide, tartrate resistant acid phosphatase type 5b. Pain sensitivity measures based on pain detection thresholds by cuff algometry, temporal summation of pain, conditioned pain modulation, and cutaneous pain sensitivity by pinprick test. Degree of depression by the Major Depression Inventory. Physical performance was assessed by Timed up and go, isomeric handgrip exercise, and postural control by force plate. Results: Serum 25(OH)D levels increased in the vitamin D treated patients compared with controls at the 12 months visit (P<0.05). Conversely, intact- Parathyroid Hormone decreased among the patients and controls receiving vitamin D compared with placebo (P<0.05). Vitamin D improved Major Depression Inventory scores in patients and controls compared with placebo (P<0.05). In patients receiving vitamin D, handgrip strength improved (P<0.05). Conclusions: Vitamin D may improve depressive symptoms, and improve handgrip strength among patients compared to controls.