Vitamin D deficiency in sickle cell disease patients in the Eastern Province of Saudi Arabia

BACKGROUND: Vitamin D deficiency (VDD) is a major global health problem. In sickle cell disease (SCD), VDD is highly prevalent, reaching up to 96% of populations. VDD may contribute to many of the complications of SCD. OBJECTIVE: Estimate the 25-hydroxyvitamin D [25(OH)D] level and the frequency of VDD and insufficiency among among SCD patients by age group and disease status. DESIGN: Analytical cross-sectional. SETTING: Ministry of Health (MOH) secondary care hospital. PATIENTS AND METHODS: Non-probability purposive sampling was used to select SCD patients, aged 12 years and older, of both sexes, who had visited the hospital during a period of 5 years (2010–2014). Blood samples were processed by electrochemiluminescence technology. MAIN OUTCOME MEASURE(S): 25(OH)D levels by demographic data, and disease activity. SAMPLE SIZE: 640 patients. RESULTS: Of those, 82% (n=523) had suboptimal 25(OH)D (0-<30 ng/mL), and 67% were deficient (0-<20 ng/mL). Patients with any SCD crisis (20.7%, 144/694) had lower 25(OH)D (median, IQR: 10.1 ng/mL [8.6] ng/mL) compared to patients without crisis (71.0%, 493/694) (15.7 ng/mL [18.2] ng/mL) (P<.001). Deficiency was more common in the younger age groups and in sickle cell anemia patients with crisis. CONCLUSIONS: VDD is highly prevalent in this population. Established vitamin D screening is a necessity, so that affected patients can be treated. LIMITATIONS: Presence of residual confounders such as nutritional status, physical activity, lack of sun exposure, medications that alleviate SCD crises (such as hydroxyurea), and comorbid illnesses. The relationship between sickle cell disease genotype and vitamin D level was not analyzed.