Association between vitamin D status and physical performance: the InCHIANTI study.
BACKGROUND
Vitamin D status has been hypothesized to play a role in musculoskeletal function. Using data from the InCHIANTI study, we examined the association between vitamin D status and physical performance.


METHODS
A representative sample of 976 persons aged 65 years or older at study baseline were included. Physical performance was assessed using a short physical performance battery (SPPB) and handgrip strength. Multiple linear regression was used to examine the association between vitamin D (serum 25OHD), parathyroid hormone (PTH), and physical performance adjusting for sociodemographic variables, behavioral characteristics, body mass index, season, cognition, health conditions, creatinine, hemoglobin, and albumin.


RESULTS
Approximately 28.8% of women and 13.6% of men had vitamin D levels indicative of deficiency (serum 25OHD < 25.0 nmol/L) and 74.9% of women and 51.0% of men had vitamin D levels indicative of vitamin D insufficiency (serum 25OHD < 50.0 nmol/L). Vitamin D levels were significantly associated with SPPB score in men (beta coefficient [standard error (SE)]: 0.38 [0.18], p =.04) and handgrip strength in men (2.44 [0.84], p =.004) and women (1.33 [0.53], p =.01). Men and women with serum 25OHD < 25.0 nmol/L had significantly lower SPPB scores whereas those with serum 25OHD < 50 nmol/L had significantly lower handgrip strength than those with serum 25OHD > or =25 and > or =50 nmol/L, respectively (p <.05). PTH was significantly associated with handgrip strength only (p =.01).


CONCLUSIONS
Vitamin D status was inversely associated with poor physical performance. Given the high prevalence of vitamin D deficiency in older populations, additional studies examining the association between vitamin D status and physical function are needed.
Houston
Denise K
DK
Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA. dhouston@wfubmc.edu
Cesari
Matteo
M
Ferrucci
Luigi
L
Cherubini
Antonio
A
Maggio
Dario
D
Bartali
Benedetta
B
Johnson
Mary Ann
MA
Schwartz
Gary G
GG
Kritchevsky
Stephen B
SB
D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D018737:Hand Strength; D006801:Humans; D015994:Incidence; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D010809:Physical Fitness; D017678:Sex Distribution; D012737:Sex Factors; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology / Q000503:physiopathology
D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D