title: Prevalence of Vitamin D Deficiency and Its Associations with Skin Color in Pregnant Women in the First Trimester in a Sample from Switzerland.
abstract: Vitamin D deficiency in pregnancy has negative clinical consequences, such as associations with glucose intolerance, and has been shown to be distributed differently in certain ethnic groups. In some countries, a difference in the rate of vitamin D deficiency was detected in pregnant women depending on their skin color. We examined the prevalence of vitamin D deficiency (<20 ng/mL) in women in early pregnancy in Switzerland and evaluated the association of skin color with vitamin D deficiency. In a single-center cohort study, the validated Fitzpatrick scale and objective melanin index were used to determine skin color. Of the 204 pregnant women included, 63% were vitamin D deficient. The mean serum 25-hydroxyvitamin D concentration was 26.1 ng/mL (95% confidence interval (CI) 24.8-27.4) in vitamin D-sufficient women and 10.5 ng/mL (95% CI 9.7-11.5) in women with deficiency. In the most parsimonious model, women with dark skin color were statistically significantly more often vitamin D deficient compared to women with light skin color (OR 2.60; 95% CI 1.08-6.22; adjusted for age, season, vitamin D supplement use, body mass index, smoking, parity). This calls for more intense counseling as one policy option to improve vitamin D status during pregnancy, i.e., use of vitamin D supplements during pregnancy, in particular for women with darker skin color.
authors.affiliation: Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Hirschengraben 84, CH-8001 Zurich, Switzerland. richard@patientensicherheit.ch.
authors.forename: Aline
authors.initials: A
authors.lastname: Richard
authors.affiliation: Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Hirschengraben 84, CH-8001 Zurich, Switzerland. sabine.rohrmann@uzh.ch.
authors.forename: Sabine
authors.initials: S
authors.lastname: Rohrmann
authors.affiliation: Clinic of Obstetrics, University Hospital Zurich, Frauenklinikstrasse 10, CH-8091 Zurich, Switzerland. katharina.quackloetscher@usz.ch.
authors.forename: Katharina C
authors.initials: KC
authors.lastname: Quack Lötscher
mesh_terms: D015331:Cohort Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D016015:Logistic Models; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood*; D037841:Pregnant People; D015995:Prevalence; D012621:Seasons; D012880:Skin Pigmentation; D013557:Switzerland / Q000453:epidemiology; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D014807:Vitamin D
keywords: Switzerland; pregnancy; skin color; vitamin D; vitamin D deficiency