Low vitamin D status in systemic sclerosis and the impact on disease phenotype

Vitamin D has pleiotropic effects including immunomodulatory, cardioprotective, and antifibrotic properties and is thus able to modulate the three main links in scleroderma pathogenesis. The aim of the study was to evaluate the level of vitamin D in patients with systemic sclerosis and to analyze the associations between the concentration of vitamin D and the features of systemic sclerosis.

Fifty-one consecutive patients were evaluated for visceral involvement, immunological profile, activity, severity scores, and quality of life. The vitamin D status was evaluated by measuring the 25hydroxy-hydroxyvitamin D serum levels.

The mean vitamin D level was 17.06±9.13 ng/dL. Only 9.8% of the patients had optimal vitamin D levels; 66.66% of them had insufficient 25(OH)D levels, while 23.52% had deficient levels. No correlation was found between vitamin D concentration and age, sex, autoantibody profile, extent of skin involvement, or vitamin D supplementation. Vitamin D levels were correlated with the diffusing capacity of the lung for carbon monoxide (p=0.019, r=0.353), diastolic dysfunction (p=0.033, r=-0.318), digital contractures (p=0.036, r=-0.298), and muscle weakness (p=0.015, r=-0.377) and had a trend for negative correlation with pulmonary hypertension (p=0.053, r=-0.29).

Low levels of vitamin D are very common in systemic sclerosis. Poor vitamin status seems to be related with a more aggressive disease with multivisceral and severe organ involvement, especially pulmonary and cardiac involvement.