Effects of Vitamin D Supplementation During Pregnancy on Birth Size: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Nutrients 2019, 11(2), 442; https://doi.org/10.3390/nu11020442
(This article belongs to the Special Issue The Role of Pregnancy Nutrition in Maternal and Offspring Health)
It is amazing that a benefit was found when so many of the trials gave such small amounts of vitamin D, and somewhat late in pregnancy
Healthy pregnancies need lots of vitamin D has the following summary
Problem | Vit. D Reduces | Evidence |
| 0. Chance of not conceiving | 3.4 times | Observe |
| 1. Miscarriage | 2.5 times | Observe |
| 2. Pre-eclampsia | 3.6 times | RCT |
| 3. Gestational Diabetes | 3 times | RCT |
| 4. Good 2nd trimester sleep quality | 3.5 times | Observe |
| 5. Premature birth | 2 times | RCT |
| 6. C-section - unplanned | 1.6 times | Observe |
| Stillbirth - OMEGA-3 | 4 times | RCT - Omega-3 |
| 7. Depression AFTER pregnancy | 1.4 times | RCT |
| 8. Small for Gestational Age | 1.6 times | meta-analysis |
| 9. Infant height, weight, head size within normal limits | RCT | |
| 10. Childhood Wheezing | 1.3 times | RCT |
| 11. Additional child is Autistic | 4 times | Intervention |
| 12.Young adult Multiple Sclerosis | 1.9 times | Observe |
| 13. Preeclampsia in young adult | 3.5 times | RCT |
| 14. Good motor skills @ age 3 | 1.4 times | Observe |
| 15. Childhood Mite allergy | 5 times | RCT |
| 16. Childhood Respiratory Tract visits | 2.5 times | RCT |
RCT = Randomized Controlled Trial
The articles in Pregnancy AND Meta-analysis are here:
- Vitamin D reduces: pre-eclampia 1.6 X, postpartum dep. 3.6 X, autism 1.5X etc. - meta-analysis March 2024
- Vitamin D supplementation decreased the risk of preeclampsia by 39% – meta-analysis Feb 2024
- Yet another reason to take Vitamin D while pregnant – fight COVID - meta-analysis May 2023
- Vitamin D during pregnancy increased child’s bone mineral density – meta-analysis April 2023
- Preeclampsia reduced by 33 percent if high vitamin D – meta-analysis Feb 2023
- Maternal pregnancy problems if Vitamin D is less than 40 ng – meta-analysis Oct 2022
- Worse COVID during 3Q pregnancy if 2.5 ng lower Vitamin D – meta-analysis Sept 2022
- Miscarriage 1.6 X more likely if low vitamin D – meta-analysis May 2022
- Recurrent Miscarriage 4X more likely if low vitamin D – meta-analysis June 2022
- Pregnancy problems (LBW, PTB, SGA) associated with low vitamin D, 42nd meta-analysis – March 2022
- Low Vitamin D associated with preeclampsia - meta-analysis Feb 2022
- Low Vitamin D associated with pre-eclampsia -40th meta-analysis – Feb 2022
- Small vitamin D doses while pregnant do not decrease infant allergies – meta-analysis Feb 2022
- Anemia 1.6 X more likely during pregnancy if low Vitamin D – meta-analysis Dec 2021
- Vitamin D reduces preeclampsia, gestational diabetes and hypertension - 38th meta-analysis Dec 2021
- Need at least 6,000 IU daily while breastfeeding to eliminate Vitamin D deficiency – meta-analysis Oct 2021
- Gestational diabetes risk reduced 1.5X by Vitamin D – meta-analysis March 2021
- Gestational Diabetes – increased risk if poor Vitamin D Receptor – 2 Meta-Analyses 2021
- Small vitamin D doses given during pregnancy do not reduce childhood asthma – meta-analysis Dec 2020
- Multiple Sclerosis 40 percent more likely if mother had low vitamin D – meta-analysis Jan 2020
- Pregnancies helped by Vitamin D (insulin and birth weight in this case) – meta-analysis Oct 2019
- Preeclampsia 2.7 X less likely if 50,000 IU of Vitamin D every 2 weeks – meta-analysis Sept 2019
- Autism risk increased 30 percent by Cesareans (both low vitamin D) – meta-analysis Sept 2019
- Vitamin D treats Gestational Diabetes, decreases hospitalization and newborn complications – meta-analysis March 2019
- Birth size and weight increased by Vitamin D – meta-analysis Feb 2019
- Pregnancies helped by Vitamin D in many ways – 27th meta-analysis Jan 2019
- Vitamin D supplementation reduced SGA, fetal mortality, infant mortality – JAMA Meta – May 2018
- Gestational Diabetes 39 percent more likely if insufficient Vitamin D – Meta-analysis March 2018
- Preeclampsia reduced 2X by Vitamin D, by 5X if also add Calcium – meta-analysis Oct 2017
- Preeclampsia risk reduced 60 percent if supplement with Vitamin D (they ignored dose size) – meta-analysis Sept 2017
- Small for gestational age is 1.6 X more likely if mother was vitamin D deficient – meta-analysis Aug 2017
- Miscarriage 2 times more likely if low vitamin D – meta-analysis May 2017
- Fewer than half of pregnancies will get even 20 ng of vitamin D with 800 IU daily dose – meta-analysis May 2017
- Low Vitamin D results in adverse pregnancy and birth outcomes – Wagner meta-analysis March 2017
- Bacterial vaginosis in pregnancy increased prematurity risk by 60 percent - meta-analysis 1999
- Preterm birth rate reduced by 43 percent with adequate Vitamin D supplementation – meta-analysis Feb 2017
- Vitamin D during pregnancy reduces risk of childhood asthma by 13 percent – meta-analysis Dec 2016
- Vitamin D helps during pregnancy – meta-analysis Feb 2016
- Preterm birth 30 percent more likely if low vitamin D – meta-analysis May 2016
- Preterm birth extended by 2 weeks with Omega-3 – Meta-analysis Nov 2015
- Gestational Diabetes Mellitus 1.5X more likely if low vitamin D – meta-analysis Oct 2015
- Infant wheezing 40 percent less likely if mother supplemented with vitamin D, vitamin E, or Zinc – meta-analysis Aug 2015
- Birth weight and length increased with high levels of vitamin D – meta-analysis March 2015
- Pregnancy and Vitamin D – meta-analysis April 2015
- More vitamin D needed during pregnancy – meta-analysis Oct 2014
- Preeclampsia rate cut in half by high level of vitamin D – meta-analysis March 2014
- Preeclampsia 2.7X more frequent if low vitamin D – meta-analysis Sept 2013
- 2X more preeclampsia when vitamin D less than 30 ng, etc. - meta-analysis March 2013
- 2X more likely to have preeclampsia if less than 20 ng of vitamin D – Meta-analysis Jan 2013
- Multiple Sclerosis 23 percent more likely if born in April vs. Oct – meta-analysis Nov 2012
Ensure a healthy pregnancy and baby - take Vitamin D before conception has the following
Download the PDF from Vitamin D Life
During pregnancy, vitamin D supplementation may be a feasible strategy to help prevent low birthweight (LBW) and small for gestational age (SGA) births. However, evidence from randomized controlled trials (RCTs) is inconclusive, probably due to heterogeneity in study design and type of intervention. A systematic literature search in the PubMed-Medline, EMBASE, and Cochrane Central Register of Controlled
Trials databases was carried out to evaluate the effects of oral vitamin D supplementation during pregnancy on birthweight, birth length, head circumference, LBW, and SGA. The fixed-effects or random-effects models were used to calculate mean difference (MD), risk ratio (RR), and 95% Confidence Interval (CI).
On a total of 13 RCTs, maternal vitamin D supplementation had a positive effect on
- birthweight (12 RCTs; MD = 103.17 g, 95% CI 62.29–144.04 g),
- length (6 RCTs; MD = 0.22 cm, 95% CI 0.11–0.33 cm), and
- head circumference (6 RCTs; MD:0.19 cm, 95% CI 0.13–0.24 cm).
In line with these findings, we also demonstrated that maternal vitamin D supplementation reduced the risk of
(LBW (3 RCTs; RR = 0.40, 95% CI 0.22–0.74) and
- SGA (5 RCTS; RR = 0.69, 95% CI 0.51–0.92).
The present systematic review and meta-analysis confirmed the well-established effect of maternal vitamin D supplementation on birth size. However, further research is required to better define risks and benefits associated with such interventions and the potential implications for public health