Multiple sclerosis, osteoporosis, and vitamin D.
Multiple sclerosis (MS) is associated with reduced bone mass and higher frequency of osteoporosis. Although high-dose short-term intravenous glucocorticoid regimens cause a decrease in bone formation, this effect is usually reversible and osteoporosis in MS patients may be independent of the short-term corticosteroid treatment. Clinical evidence suggests an important role of vitamin D as a modifiable risk factor in MS. Low circulating levels of vitamin D have been found in MS patients, especially during relapses, suggesting that vitamin D could be involved in the regulation of the clinical disease activity. Vitamin D mediates its function through a single vitamin D receptor (VDR). Polymorphisms of the VDR have major effects on vitamin D function and metabolism, and some VDR genotypes have been linked to osteoporosis and MS. Because the safety of high doses of vitamin D has not been established yet, vitamin D hasn't been used in enough doses to increase the serum level to a desired therapeutic target. Future clinical trials should determine the upper limit of vitamin D intake in order to achieve therapeutic benefit in MS patients.
Department of Nuclear Medicine, University Hospital of Ioannina, Ioannina, Greece.
Chrissa
C
Sioka
Athanassios P
AP
Kyritsis
Andreas
A
Fotopoulos
D000305:Adrenal Cortex Hormones / Q000009:adverse effects; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism / Q000503:physiopathology; D015897:Comorbidity; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000235:genetics / Q000378:metabolism; D010024:Osteoporosis / Q000453:epidemiology* / Q000235:genetics / Q000378:metabolism; D018167:Receptors, Calcitriol / Q000235:genetics; D014807:Vitamin D / Q000378:metabolism / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000453:epidemiology* / Q000235:genetics / Q000378:metabolism
D000305:Adrenal Cortex Hormones; D018167:Receptors, Calcitriol; D014807:Vitamin D