Clinical and serological association of plasma 25-hydroxyvitamin D levels in lupus and the short-term effects of oral vitamin D supplementation

In phase one, 702 South Asian lupus patients (mean age 29.5) had median plasma vitamin D of 22.83 ng/ml, with deficiency below 20 ng/ml in 41.5%; levels were far higher in South India (27.06 ng/ml) than North India (17.15 ng/ml, p < 0.01). Vitamin D correlated only weakly and negatively with disease activity (SLEDAI-2K), and on regression the strongest predictors were recruitment centre (beta 4.37) and age (beta 0.18), not disease activity. In phase two, 91 patients were randomised to high-dose (60,000 U weekly x5 then monthly) or routine-dose (30,000 U monthly) oral vitamin D for 6 months; the high dose raised levels more (median rise 9.5 vs 2.6 ng/ml, p = 0.04). Lupus flares (14 in total) and six minor adverse events were distributed equally between the two dose groups.