RT Journal
A1 Wilber ST, Sullivan AF, Camargo CA
T1 CHronic pain and risk of falls in older adults
JF JAMA
JO JAMA
YR 2010
FD March 24
VO 303
IS 12
SP 1147
OP 1149
DO 10.1001/jama.2010.324
UL http://dx.doi.org/10.1001/jama.2010.324
AB 
Another potential explanation is vitamin D deficiency. A recent analysis of data from the National Health and Nutrition Examination Survey found that 30% of US adults aged 65 years and older had serum 25-hydroxyvitamin D levels less than 20 ng/mL, and an additional 38% had serum 25-hydroxyvitamin D levels less than 30 ng/mL (to convert to nmol/L, multiply by 2.496).2 It would be helpful to know whether Leveille et al tested for baseline levels of serum 25-hydroxyvitamin D in their cohort.