The Effect of Vitamin D Supplementation on Hepcidin, Iron Status, and Inflammation in Pregnant Women in the United Kingdom

Braithwaite VS¹, Crozier SR², D’Angelo S³, Prentice A⁴, Cooper C^5,^6,⁷, Harvey NC^8,⁹, Jones KS^10,¹¹; MAVIDOS Trial Group.

Author information

^{1 – MRC Elsie Widdowson Laboratory, Cambridge CB1 9NL, UK. vb287@cam.ac.uk.}
^{2 – MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK. src@mrc.soton.ac.uk.}
^{3 – MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK. sd@mrc.soton.ac.uk.}
^{4 – MRC Elsie Widdowson Laboratory, Cambridge CB1 9NL, UK. ann.prentice@mrc-lmb.cam.ac.uk.}
^{5 – MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK. cc@mrc.soton.ac.uk.}
^{6 – NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK. cc@mrc.soton.ac.uk.}
^{7 – Oxford NIHR Biomedical Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, The Botnar Research Centre, University of Oxford, Oxford OX1 2JD, UK. cc@mrc.soton.ac.uk.}
^{8 – MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK. nch@mrc.soton.ac.uk.}
^{9 – NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK. nch@mrc.soton.ac.uk.}
^{10 – MRC Elsie Widdowson Laboratory, Cambridge CB1 9NL, UK. kerry.jones@mrc-epid.cam.ac.uk.}
^{11 – NIHR BRC Nutritional Biomarker Laboratory, University of Cambridge, Cambridge CB2 0AH, UK. kerry.jones@mrc-epid.cam.ac.uk.}

Abstract

Iron and vitamin D deficiencies are common during pregnancy. Our aim was to identify whether antenatal vitamin D₃ supplementation affects iron status (via hepcidin suppression) and/or inflammation. Using a subset of the UK multicenter Maternal Vitamin D Osteoporosis Study (MAVIDOS)-a double-blinded, randomized, placebo-controlled trial (ISRCTN82927713; EudraCT2007-001716-23)-we performed a secondary laboratory analysis. Women with blood samples from early and late pregnancy (vitamin D₃ (1000 IU/day from ~14 weeks gestation n = 93; placebo n = 102) who gave birth in the springtime (March⁻May) were selected as we anticipated seeing the greatest treatment group difference in change in 25-hydroxyvitamin D (25OHD) concentration. Outcomes were hepcidin, ferritin, C-reactive protein, and α1-acid glycoprotein concentration in late pregnancy (25OHD concentration was measured previously). By late pregnancy, 25OHD concentration increased by 17 nmol/L in the vitamin D₃ group and decreased by 11 nmol/L in the placebo group; hepcidin, ferritin, and inflammatory markers decreased but no treatment group differences were seen. In late pregnancy, positive relationships between 25OHD and hepcidin and 25OHD and ferritin in the placebo group were observed but not in the treatment group (group × 25OHD interaction, p < 0.02). Vitamin D₃ supplementation had no effect on hepcidin, ferritin, or inflammatory status suggesting no adjunctive value of vitamin D₃ in reducing rates of antenatal iron deficiency.

KEYWORDS: C-reactive protein; Vitamin D; ferritin; hepcidin; inflammation; pregnancy