Vitamin D During Pregnancy and Maternal, Neonatal and Infant Health Outcomes:

A Systematic Review and Meta-analysis

Andrew Thorne-Lyman1,*, Wafaie W. Fawzi1,2,3
Paediatric and Perinatal Epidemiology
Special Issue: Improving maternal, newborn, and child health outcomes through better designed policies and programs that enhance the nutrition of women
Volume 26, Issue Supplement s1, pages 75–90, July 2012

Vitamin D has well-defined classical functions related to calcium metabolism and bone health but also has non-classical effects that may influence other aspects of health. There has been considerable recent interest in the role of vitamin D on outcomes related to pregnancy and young child health but few efforts have been made to systematically consolidate this evidence to inform the research and policy agenda for low-income countries. A systematic review was undertaken to identify intervention and observational studies of vitamin D supplementation, intake or status (25-hydroxy-vitamin D) during pregnancy on perinatal and infant health outcomes. Data from trials and observational studies isolating the effect of vitamin D supplementation and intake were extracted and study quality was evaluated. Meta-analysis was used to pool effect estimates. We identified five randomised trials with outcomes of relevance to our review. All had small sample size and dosage amount, duration and frequency varied as did the ability to correct deficiency.

Pooled analysis of trials using fixed-effects models suggested protective effects of supplementation on

• low birthweight (three trials, risk ratio (RR) = 0.40 [95% confidence interval (CI) 0.23, 0.71]) and
• non-significant but suggestive effects of daily supplementation on
  small-for-gestational age (two trials, RR = 0.67 [0.40, 1.11]).
• No effect on preterm delivery (<37 weeks) was evident (two trials, RR = 0.77 [0.35, 1.66]).
• Little evidence from trials exists to evaluate the effect of vitamin D supplementation during pregnancy on maternal, perinatal or infant health outcomes.

Based on both trials and observational studies, we recommend that future research explore small-for-gestational age, preterm delivery, pre-eclampsia, and maternal and childhood infections, as outcomes of interest. Trials should focus on populations with a high prevalence of vitamin D deficiency, explore the relevance of timing of supplementation, and the dosage used in such trials should be sufficient to correct deficiency.

PDF is attached at the bottom of this page
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Comment by VitaminDWiki

Yet another meta-analysis which ignores the type and amount of vitamin D in each trial
A trial using 800 IU of vitamin D2 is given the same weight as another trial which used 200,000 IU (hopefully of D3 - it does not say)

See also VitaminDWiki

• Premature or low birth weight resulted in children 3X more likely to be anxious – May 2011
• 7X more likely to have low birth weight babies when mother very low on vitamin D – March 2010
• Arab pre-term infants often have less than 10 ng of vitamin D - 2010
• Pre-term births report USA-Today May 2012
  Of all births: US Blacks 17%, US whites 11%, Germany 9%, UK Canada, Australia 8%, France 7%, Japan 6%
  For 62 out of 65 countries, the rate of premature births has been increasing
  comment by a reader " maternal obesity which increases chance of premature delivery 30%" see original 126 page study
• Low birth weight 3X more likely if mother had less than 25 nanograms of vitamin D – May 2012
• Overview Dark Skin and Pregnancy
• Overview Pregnancy and vitamin D which had the following table Aug 2012

IU	Cumulative Benefit	Blood level	Cofactors	Calcium	$*/year
400	Less Rickets (but not zero with 400 IU) 3X less adolescent Schizophrenia Fewer child seizures	20-30 ng/ml	Not needed	No effect	$3
2000	2X More likely to get pregnant naturally/IVF 2X Fewer dental problems with pregnancy 8X less diabetes 4X fewer C-sections (>37 ng) 4X less preeclampsia (40 ng vs 10 ng) 5X less child asthma 2X fewer language problems age 5	42 ng/ml	Desirable	< 750 mg	$15
4000	2X fewer pregnancy complications 2X fewer pre-term births	49 ng/ml	Must have cofactors	< 750 mg	$75
6000	Probable: larger benefits for above items Perhaps prevent 2nd autistic child    clinical trials underway Just enough D for breastfed infant		Must have cofactors	< 750 mg	$85

See also in VitaminDWiki: High risk of being vitamin D deficient during pregnancy

• Potential high risk if : dark skin, twins, recent pregnancy, smoking, very far from equator, obese, excessive clothes,
• Very low vitamin D for first pregnancies and those with dark skin – Jan 2011
• Low vitamin D probable cause of descrepancy of black and white birth outcomes - 2010.pdf
• Assess your level of vitamin D deficiency - especially if dark skin, far from equator, medical condition, ..
• Black = 97% Hispanic = 81%, White = 67% Pregnant women vitamin D insufficient – July 2010
• Overview of Obesity and Vitamin D Obese people have significant lower levels of vitamin D
• Should consider loading up on vitamin D very early in the pregnancy if high risk of vitamin D deficiency
  Typical loading dose: 200,000 IU spread over 2 months
• Low cost tests   instant free test to see if anyone is extremely low on vitamin D