High Prevalence of Hypovitaminosis D in Cutaneous and Systemic Lupus Erythematosus Patients and Its Associated Factors: A Cross-Sectional Study in Thailand

Abstract

Objective To investigate the prevalence of low vitamin D levels in patients with cutaneous lupus erythematosus (CLE) and systemic lupus erythematosus (SLE) in Thailand and determine the influential factors associated with inadequate levels. Methods The medical records of patients diagnosed with SLE and/or CLE and evaluated for serum 25-OH vitamin D were retrospectively reviewed from January 2014 to January 2021. Vitamin D deficiency (<20 ng/mL) and insufficiency (21–29 ng/mL) were indicated, and predictors of hypovitaminosis D were identified by multiple linear regression analysis. Results In total, 414 patients with SLE and/or CLE were included in the study. Vitamin D deficiency was predominant in the CLE-only group (33.3%), followed by SLE without CLE (15.6%) and SLE with CLE (8%), p < 0.001. Likewise, vitamin D insufficiency was more prevalent in the CLE-only group (44.4%) compared to SLE with (35.8%) and without CLE (40%). Multivariate analysis showed that a higher SLEDAI-2K score and female sex had a negative association with vitamin D levels, while an intake of every 10,000 IU of vitamin D2 per week increased serum vitamin D levels by up to 2.37 ng/mL. Furthermore, forty-five percent of patients continued to have vitamin D depletion despite commencing the recommended doses of vitamin D replacement. Conclusion Approximately half of Thai patients with SLE and 80% of CLE had vitamin D inadequacy. Vitamin D replacement is a good predictor of high serum vitamin D levels, while lower serum levels were associated with higher disease severity. Therefore, serum vitamin D monitoring and supplementation are suggested for all lupus erythematosus cases, especially those with CLE.

Prevalence of thyroid dysfunctions and thyroid autoantibodies in Thai patients with systemic lupus erythematosus: An age‐ and sex‐matched controlled study

“…This condition also has been associated with severe vitamin D deficiency and insulin resistance 25 . Vitamin D deficiency has been reported in Thai SLE patients with the prevalence of 13.8%, 26 therefore it might be another cause of the high isolated hypothyroxinemia prevalence in this study. However, all of the patients in this study were given calcium and vitamin D supplementation together with corticosteroid treatment to prevent glucocorticoid induced osteoporosis; therefore, the possibility of them having vitamin D deficiency should be minimal.…”