Abstract
〈Objective〉 Vitamin D deficiency is common in Japan and associated with the development of various diseases. Since the measurement of serum 25-hydroxyvitamin D (25(OH)D) is costly, vitamin D status cannot be easily screened in healthy subjects. Therefore, we tried to prepare a simple questionnaire for vitamin D deficiency.
〈Methods〉 The study was performed in Nagano and Kumamoto Prefectures from August 2015 to December 2016. The subjects taking routine medication potentially interfering with vitamin D status was excluded. The questionnaire and blood sample were simultaneously collected. Vitamin D deficiency was defined as the level of serum 25(OH)D <20 ng/mL.
〈Results〉 Of one hundred and three participants (mean age 44.2 years, M/F; 32/71), 33% of them had vitamin D deficiency. In univariate analysis, “living in Kumamoto” (OR 22.2, 95% CI 7.73- 65.2, p<0.001) and “sunscreen use in legs and arms” (OR 2.89, 95% CI 1.20-6.94 p=0.02) were risks for vitamin D deficiency. “Living in Kumamoto” remained a significant predictor in multivariate analysis (OR 53.0, 95% CI 12.5- 224, p<0.001). The percentage of subjects with sunscreen use was significantly higher in Kumamoto than in Nagano.
〈Conclusions〉 Sunscreen use is an important determinant of vitamin D status. Accordingly, the use of sunscreen must be included in the questionnaire for vitamin D deficiency in Japanese subjects.
