OBJECTIVE: To investigate 25-OH
vitamin D concentrations in 2 independent
systemic sclerosis (
SSc) populations from France and Italy. METHODS: We studied 156 consecutive
SSc patients comparable for demographic characteristics: 90 from Northern France and 66 from Southern Italy. 25-OH
vitamin D, intact
parathyroid hormone, and serum total
calcium and
phosphorus were measured in all patients.
Vitamin D concentrations < 30 ng/ml were considered insufficiency, while values < 10 ng/ml were classified as deficiency. RESULTS:
Vitamin D insufficiency and deficiency rates were very high and comparable between the 2 populations: 74/90 (82%) versus 57/66 (86%) for insufficiency and 29/90 (32%) versus 15/66 (23%) for deficiency, respectively, in the French and Italian patients. They were not influenced by
vitamin D supplementation, which was not
statistically different in the 2 groups. In the combined populations, a significant negative
correlation was found between low
vitamin D levels and European Disease Activity Score (p = 0.04, r = -0.17) and an even more significant
correlation was found with acute-phase
reactants (p = 0.004, r = -0.23 for
erythrocyte sedimentation rate), and low levels of
vitamin D were associated with the systolic
pulmonary artery pressure (sPAP) estimated by
echocardiography (p = 0.004). In
multivariate analysis,
vitamin D deficiency was associated with sPAP (p = 0.02). CONCLUSION:
Vitamin D deficiency was very common in the 2
SSc populations, independent of geographic origin and
vitamin D supplementation. This suggests that common
vitamin D supplementation does not correct the deficiency in
SSc patients, and that a higher dose is probably needed, especially in those with high
inflammatory activity or severe disease.
