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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Publications at this Location » Publication #353928
Title: Changes in plasma concentrations of 25-hydroxyvitamin D and 1,25 dihydroxyvitamin D during pregnancy: a Brazilian cohort.

Author
item FIGUEIREDO, ACC - Universidade Federal Do Rio De Janeiro
item COCATE, PG - Universidade Federal Do Rio De Janeiro
item ADEGBOYE, ARA - Westminster College
item FRANCO-SENA, AB - Universidade Federal Do Rio De Janeiro
item FARIAS, DR - Universidade Federal Do Rio De Janeiro
item TRINIDADE DE CASTRO, MB - Universidade Federal Do Rio De Janeiro
item BRITO, ALEX - University Of Moscow
item Allen, Lindsay - A
item MOKHTAR, RR - Boston University
item HOLICK, MF - Boston University
item KAC, G - Universidade Federal Do Rio De Janeiro

Submitted to: European Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2017
Publication Date: 4/1/2018
Citation: Figueiredo, A., Cocate, P., Adegboye, A., Franco-Sena, A., Farias, D., Trinidade De Castro, M., Brito, A., Allen, L.H., Mokhtar, R., Holick, M., Kac, G. 2018. Changes in plasma concentrations of 25-hydroxyvitamin D and 1,25 dihydroxyvitamin D during pregnancy: a Brazilian cohort. European Journal of Nutrition. 57:1059-1072. https://doi.org/10.1007/s00394-017-1389-z.
DOI: https://doi.org/10.1007/s00394-017-1389-z

Interpretive Summary: This research was designed to follow the changes in vitamin D metabolites, 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D], throughout pregnancy. A cohort of 229 apparently healthy pregnant women was followed at 5–13, 20–26, and 30–36 weeks of pregnancy. Serum 25(OH)D and 1,25(OH)2D concentrations were measured by liquid chromatography-mass spectrometry. Statistical analyses included longitudinal linear mixed-effects models adjusted for parity, season, education, self-reported skin color, and pre-pregnancy body mass index. Vitamin D status was defined based on serum 25(OH)D concentrations according to the Endocrine Society Practice Guideline and Institute of Medicine (IOM) for adults. The prevalence of serum 25(OH)D' <75 nmol/L was 70.4, 41.0, and 33.9%; the prevalence of 25(OH)D' <50 nmol/L was 16.1, 11.2, and 10.2%; and the prevalence of 25(OH)D '<30 nmol/L was 2, 0, and 0.6%, at the first, second, and third trimesters, respectively. There was an increase in serum 25(OH)D and 1,25(OH)2D throughout pregnancy. Women who started the study in winter, spring, or autumn had a longitudinal increase in 25(OH)D concentrations during pregnancy, while those who started during summer did not. The increase in 1,25(OH)2D concentrations over time in women with insufficient vitamin D (50–75 nmol/L) at baseline was larger compared to women with sufficient vitamin D at baseline. We conclude that the prevalence of vitamin D inadequacy varied significantly according to the serum cutpoint used (<75, <50 or <30 nmol/L). There was a seasonal variation in serum 25(OH)D during pregnancy. Women with inadequate vitamin D status had larger increases in the serum 1,25(OH)2D during pregnancy compared to those who had adequate vitamin D status.

Technical Abstract: Purpose To characterize the physiological changes in 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] throughout pregnancy. Methods Prospective cohort of 229 apparently healthy pregnant women followed at 5th–13th, 20th–26th, and 30th–36th gestational weeks. 25(OH)D and 1,25(OH)2D concentrations were measured by LC–MS/MS. Statistical analyses included longitudinal linear mixed-effects models adjusted for parity, season, education, self-reported skin color, and pre-pregnancy BMI. Vitamin D status was defined based on 25(OH)D concentrations according to the Endocrine Society Practice Guideline and Institute of Medicine (IOM) for adults. Results The prevalence of 25(OH)D' <75 nmol/L was 70.4, 41.0, and 33.9%; the prevalence of 25(OH)D' <50 nmol/L was 16.1, 11.2, and 10.2%; and the prevalence of 25(OH)D '<30 nmol/L was 2, 0, and 0.6%, at the first, second, and third trimesters, respectively. Unadjusted analysis showed an increase in 25(OH)D (ß'='0.869; 95% CI 0.723–1.014; P'<'0.001) and 1,25(OH)2D (ß'='3.878; 95% CI 3.136–4.620; P'<'0.001) throughout pregnancy. Multiple adjusted analyses showed that women who started the study in winter (P'<'0.001), spring (P'<'0.001), or autumn (P'='0.028) presented a longitudinal increase in 25(OH)D concentrations, while women who started during summer did not. Increase in 1,25(OH)2D concentrations over time in women with insufficient vitamin D (50–75 nmol/L) at baseline was higher compared to women with sufficient vitamin D (=75 nmol/L) (P'='0.006). Conclusions The prevalence of vitamin D inadequacy varied significantly according to the adopted criteria. There was a seasonal variation of 25(OH)D during pregnancy. The women with insufficient vitamin D status present greater longitudinal increases in the concentrations of 1,25(OH)2D in comparison to women with sufficiency.