Despite more than half of the cohort taking vitamin D supplements, 58% of Thai patients with systemic lupus erythematosus had vitamin D deficiency or insufficiency, according to recent study results.
Researchers in Thailand conducted a cross-sectional study of 101 patients with systemic lupus erythematosus (SLE; mean age, 40.13 years; 96% women). Blood samples were collected and stored. Radioimmunoassay was used to measure levels of serum 25(OH) vitamin D (25[OH]D). Vitamin D deficiency and insufficiency were considered at 30 ng/mL and 20 ng/mL, respectively. After demographic, clinical and laboratory data were collected, univariate and multivariate linear regression analyses were used to examine their associations with 25(OH)D level.
The mean level of 25(OH)D was 27.9. Vitamin D deficiency was present in 17 patients, 41 patients were vitamin-D insufficient, and 43 patients had normal levels. Vitamin D supplements were used by two-thirds of the patients, although only 29% were taking 800 IU daily.
When adjusted for age and disease duration, current daily glucocorticoid dose (b=–0.207; 95% CI, –0.384 to –0.029) and serum creatinine levels (b=–3.770; –6.208 to –1.332) negatively correlated with vitamin D levels.
Disease activity or damage and 25(OH)D levels displayed no association.
“We found a high prevalence of vitamin D insufficiency in Thai SLE patients despite most of the patients receiving some vitamin D supplementations,” the researchers concluded. “It might be useful to give at least 2,000 IU of vitamin D per day in patients with SLE.
“Higher current daily doses of glucocorticoid and higher serum creatinine were associated with lower 25(OH)D levels. Assessing serum 25(OH)D levels might be useful in patients with high serum creatinine and taking high daily doses of glucocorticoid because these patients may need higher daily doses of vitamin D supplementations.”