Vitamin D in women with class II/III obesity: Findings from the DieTBra trial

Objective: To assess the prevalence of vitamin D deficiency and factors associated with serum vitamin D levels in adult women with class II/III obesity.Methods: We analysed baseline data from 128 adult women with class II/III obesity i.e. BMI >= 35 kg/m2 who participated in the DieTBra clinical trial. Sociodemographic, lifestyle, sun exposure, sunscreen, di-etary intake of calcium and vitamin D, menopause, diseases, medication, and body composition data were analysed using multiple linear regression.Results: 128 women had mean BMI 45.53 +/- 6.36, mean age 39.7 +/- 8.75 kg/m2 and serum vitamin D 30.02 ng/ml +/- 9.80. Vitamin D deficiency was 14.01%. There was no association between serum vitamin D levels and BMI, body fat percentage, total body fat and waist circumference. Age group (p = 0.004), sun exposure/day (p = 0.072), use of sunscreen (p = 0.168), inadequate calcium intake (p = 0.030), BMI (p = 0.192), menopause (p = 0.029) and lipid-lowering drugs (p = 0.150) were included in the multiple linear regression. The following remained associated with low serum vitamin D: being 40-49 years (p = 0.003); >= 50 years of age (p = 0.020) and inadequate calcium intake (p = 0.027).Conclusion: The prevalence of vitamin D deficiency was lower than expected. Lifestyle, sun exposure and body composition were not associated. Age over 40 years and inadequate calcium intake were signifi-cantly associated with low serum vitamin D levels.(c) 2023 The Author(s). Published by Elsevier Ltd on behalf of European Society for Clinical Nutrition and Metabolism. This is an open access article under the CC BY license (http://creativecommons.org/licenses/ by/4.0/).