Treatment of vitamin D deficiency increases lower limb muscle strength in institutionalized older people independently of regular physical activity: a randomized double-blind controlled trial.
OBJECTIVE
To investigate the effects of a 6-month supplementation with calcium and cholecalciferol on biochemical parameters and muscle strength of institutionalized elderly.


METHODS
This prospective, double-blind, placebo-controlled, randomized trial included Brazilian institutionalized people > or =60 years of age receiving a 6-month supplementation (December to May) of daily calcium plus monthly placebo (calcium/placebo group) or daily calcium plus oral cholecalciferol (150,000 IU once a month during the first 2 months, followed by 90,000 IU once a month for the last 4 months; calcium/vitamin D group). Fasting blood samples for 25(OH)D, PTH and calcium determination were collected (n = 56) and muscle tests were performed (n = 46) to measure the strength of hip flexors (SHF) and knee extensors (SKE) before (baseline) and after the 6-month intervention (6 months).


RESULTS
Due to seasonal variations, serum 25(OH)D significantly enhanced in both groups after treatment, but the calcium/vitamin D group had significantly higher 25 (OH)D levels than the calcium/placebo group (84 vs. 33%, respectively; p < 0.0001). No cases of hypercalcemia were observed. While the calcium/placebo group showed no improvement in SHF and SKE at 6 months (p = 0.93 and p = 0.61, respectively), SHF was increased in the calcium/vitamin D group by 16.4% (p = 0.0001) and SKE by 24.6% (p = 0.0007).


CONCLUSIONS
The suggested cholecalciferol supplementation was safe and efficient in enhancing 25(OH)D levels and lower limb muscle strength in the elderly, in the absence of any regular physical exercise practice.
Moreira-Pfrimer
Linda D F
LD
Division of Endocrinology, School of Medicine, Federal University of São Paulo/UNIFESP, São Paulo, Brazil. lindapfrimer@hotmail.com
Pedrosa
Márcia A C
MA
Teixeira
Luzimar
L
Lazaretti-Castro
Marise
M
D000368:Aged; D000369:Aged, 80 and over; D002112:Calcifediol / Q000097:blood; D002118:Calcium / Q000008:administration & dosage / Q000097:blood; D002762:Cholecalciferol / Q000627:therapeutic use*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006707:Homes for the Aged; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D009735:Nursing Homes; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D012621:Seasons; D011795:Surveys and Questionnaires; D014808:Vitamin D Deficiency / Q000188:drug therapy* / Q000503:physiopathology
D010281:Parathyroid Hormone; D002762:Cholecalciferol; D010758:Phosphorus; D002112:Calcifediol; D002118:Calcium