Objectives: We have previously shown that MS patients have significant
ly reduced bone mass and a high prevalence of abnormal vitamin D statu
s. The object of this study was to characterize the frequency of adult
hood fractures in MS patients, prospectively determine rates of bone l
oss in MS, and determine whether vitamin D status is a predictor of bo
ne loss. Methods: MS patients (36 women, 18 men) were compared with ag
e- and gender-matched healthy controls (35 women, 14 men). Bone mass w
as performed by dual x-ray absorptiometry at baseline and at 12-month
intervals over 2 years. Results: Fractures in the absence of major tra
uma had occurred in 2% of controls and 22% of MS patients (p < 0.002),
Over the 2 years of prospective follow-up, both women and men with MS
lost substantially more bone in the femoral neck than did controls (3
% and 6% per year in pre- and postmenopausal women with MS versus 0.5%
and 0.8% per year in controls; 7.3% per year in men with MS versus 1.
6% per year in controls). Bone loss in the spine was also greater in w
omen with MS than in controls (1.6 to 3.5% per year loss in MS patient
s versus no change in controls). Duration of steroid treatment beyond
5 months and ambulatory status were both predictors of bone loss. Bone
loss in the spine occurred faster in MS patients with low (<20 ng/mL)
25-hydroxyvitamin D levels (1.9% per year, p < 0.04), whereas in thos
e with normal 25-hydroxyvitamin D levels, bone loss was insignificant.
At the femoral neck, bone loss was substantial in all patients, but w
as somewhat faster in the group with low levels of 25-hydroxyvitamin D
(5.6% per year, p < 0.0001) compared with the group with high levels
of 25-hydroxyvitamin D (4.3% per year, p = 0.03). Conclusions: MS pati
ents have more frequent fractures and lose bone mass more rapidly than
do their healthy age- and gender-matched peers, in part related to in
sufficient vitamin D. Vitamin D repletion in MS patients who are defic
ient might reduce, to some extent, the rate of bone loss and decrease
osteoporosis-related fractures.