Different prenatal multivitamins in pregnancy Original paper

In this randomized controlled trial, women who took a multivitamin (compared to the same multivitamin plus vitamin D and other B vitamins) had higher rates of vitamin deficiencies before and during pregnancy, but not after pregnancy.

This Study Summary was published on April 2, 2024.

Quick Summary

In this randomized controlled trial, women who took a multivitamin (compared to the same multivitamin plus vitamin D and other B vitamins) had higher rates of vitamin deficiencies before and during pregnancy, but not after pregnancy.

What was studied?

The effect of supplementing with 2 different prenatal multivitamins on vitamin levels in the context of pregnancy.

The researchers measured serum levels of vitamin D, folate, vitamin B2, vitamin B6 (pyridoxal 5-phosphate), vitamin B12 and homocysteine (which is indicative of the levels of several B-vitamins, but most notably folate and vitamins B6 and B12).

Who was studied?

580 women (average age of 30) without known health conditions who were planning on becoming pregnant.

How was it studied?

In this randomized controlled trial conducted in Singapore, New Zealand, and the UK, the participants were divided into 2 groups. Each group took a liquid prenatal multivitamin twice per day from preconception until delivery.

The control group received the following:

The experimental group received the same multivitamin as the control group, plus the following:

  • 400 IU/day of vitamin D
  • 1.8 mg/day of vitamin B2
  • 2.6 mg/day of vitamin B6
  • 5.2 µg/day of vitamin B12
  • 10 mg/day of zinc
  • 4 grams/day of myo-inositol
  • 10 billion colony-forming units/day of each of Lactobacillus rhamnosus and Bifidobacterium animalis (probiotics)

The study outcomes were measured at 5 time points: T1 (the first time the outcomes were measured; at recruitment), T2 (preconception, but 1 month after commencing the intervention), T3 (early pregnancy; 7–11 weeks gestation), T4 (late pregnancy; around 28 weeks gestation), and T5 (6 months after delivery).

What were the results?

The following differences were observed in the experimental group compared to control group:

  • Lower rates of vitamin D deficiency and insufficiency at T2–T4
  • Lower rates of low and marginal vitamin B2 status at T2–T4
  • Lower rates of low vitamin B6 status at T3–T4
  • Lower rates of vitamin B12 deficiency at T4 and vitamin B12 depletion at T1–T5*
  • Lower (improved) average levels of homocysteine at T2–4

Anything else I need to know?

Vitamin D deficiency and insufficiency were defined as less than 50 and 75 nanomoles per liter (less than 20 and 30 ng/mL), respectively. Vitamin B12 deficiency and depletion were defined as levels less than 148 and 221 picomoles per liter, respectively.

Average homocysteine levels, although they were lower in the experimental group, were no different when comparing the number of participants in the experimental group with high homocysteine to the control group.

This study consisted of an analysis of some of the many secondary outcomes from a different study conducted with the same population,[1] in which the primary outcome was glucose tolerance as assessed by an oral glucose tolerance test.

* Vitamin B12 depletion rates were higher at T1 (baseline) in the experimental group compared to the control group and lower at T2–T5 in the experimental group compared to the control group.

This Study Summary was published on April 2, 2024.