In 2025, a study published in *Nutrition Reviews 2025* reviewed 30 trials involving women before, during and after pregnancy. The results suggested improved micronutritional status and significant reductions in various adverse outcomes. These findings provide guidance on nutrition during preconception, pregnancy and lactation.
For the search term ‘Pregnancy’ (embargo in English), the findings emphasise adequate nutrition throughout the reproductive period. The scope includes women trying to conceive, those who are pregnant or breastfeeding, along with outcomes observed in their children.
The review brought together 30 trials covering the entire reproductive period
It was a systematic review of studies that used multi-micronutrient supplements at some point during the reproductive journey. The search identified publications from around the world spanning 30 years. MMS refers to supplementation with multiple vitamins and minerals in a single formulation.
The trials involved healthy women, women with infertility, those at risk of recurrent miscarriage, and women who were pregnant or breastfeeding in various countries. The review also compiled findings relating to children.
The trials showed significant improvements in nutritional markers
In healthy women in Germany, MMS significantly increased erythrocyte folate levels compared with placebo. This marker measures the folate stored within red blood cells. Levels considered protective were achieved within four weeks.
Several trials also recorded significant reductions in homocysteine levels compared with placebo or baseline values. Homocysteine is an amino acid associated with adverse outcomes when levels are elevated.
The review reported significant reductions in congenital anomalies and neural tube defects during early pregnancy. These outcomes are clinically relevant, whilst folate and homocysteine represent measurable biological changes.
The MMS containing 800 µg of folic acid was significantly more effective than 400 µg of folic acid alone. During breastfeeding, some trials observed significant improvements in the nutrient content of breast milk and blood. A reduction in postnatal depression was also reported.
Folate, iron and B vitamins support essential maternal processes
Folate is involved in the synthesis of DNA and RNA, the building blocks that enable cells to form and divide. The neural tube begins to close during the first four weeks after conception.
Vitamins B2, B6 and B12 work alongside folate in pathways related to blood, energy and homocysteine. Iron forms part of haemoglobin, the protein that transports oxygen around the body.
Low iron stores can contribute to iron-deficiency anaemia when the mother’s requirements increase. Vitamin C acts as an antioxidant and helps to maintain cellular balance.
Nutritional status becomes important even before conception
The review cites insufficient levels of iron, zinc or folate in 69 per cent of women of reproductive age worldwide. This deficiency can occur without clear symptoms and is known as ‘hidden hunger’.
The requirements for numerous micronutrients increase during pregnancy and breastfeeding due to foetal and placental development. Professional monitoring allows nutrients and their quantities to be tailored to each woman.
Safety was favourable and the review establishes specific limits
Very few adverse events were reported in infants. Almost all were considered unrelated to MMS intake. There was no overall increased frequency of complications compared with placebo, other supplements or no supplementation.
Some studies reported mild gastrointestinal discomfort compared with placebo. One cohort study linked periconceptional use with an increased incidence of otitis media and childhood atopic dermatitis. The authors noted possible effects of multiple comparisons and family history.
The review focused primarily on a specific prenatal formulation. Three authors were employees of Bayer, the company that designed and funded the review. The trials varied in terms of countries, stages, doses and comparators.
These factors limit the direct generalisation of individual findings. The clinical results apply to the populations, formulations and doses assessed. Individual decisions require guidance from a healthcare professional.
Nutribiolite Iron Complex brings together key nutrients from the review
The key combination includes iron, folate, vitamins B2, B6 and B12, and vitamin C. Nutribiolite Iron Complex combines these nutrients in a single daily vegetarian capsule.
Each capsule provides 20 mg of iron bisglycinate and 80 mg of vitamin C. It also contains 400 µg of L-5-MTHF folate, vitamin B6 as P5P, and vitamins B2 and B12 as methylcobalamin.
Ferrous bisglycinate offers high absorption and good digestive tolerance. Its structure binds ferrous iron to two glycine molecules. Vitamin C enhances iron absorption.
The active forms of B6, B12 and folate allow them to be utilised directly by the body. Iron contributes to the formation of red blood cells and haemoglobin and supports normal oxygen transport.
Vitamins B6 and B12 contribute to the normal formation of red blood cells. Folate supports normal blood formation and cell division. Vitamin B2 supports the normal maintenance of red blood cells and iron metabolism.
The formula contributes to normal energy metabolism and helps reduce tiredness and fatigue. It is vegan and contains no added sugars, artificial colourings or flavourings. It uses cassava starch and L-leucine as plant-based excipients.
It combines iron bisglycinate, vitamins C, B2, B6 and B12, and L-5-MTHF folate – key nutrients in this review.
The evidence and the formula address five practical questions
What was the main finding of the review?
It pooled 30 trials and suggested improvements in micronutritional status. It also reported statistically significant reductions in several adverse pregnancy outcomes.
Which population did the review include?
It included women trying to conceive, pregnant women and breastfeeding women. Some trials studied healthy women, whilst others included specific clinical settings.
How do folate and iron function during this stage?
Folate is involved in DNA synthesis and cell division. Iron is a component of haemoglobin, which transports oxygen.
How does the study relate to the Iron Complex?
The formula provides iron bisglycinate, 400 µg of L-5-MTHF folate and vitamins B2, B6, B12 and C.
How should the product be used and what precautions should be taken?
Take one capsule a day with a glass of water. The pack provides up to four months’ continuous supplementation. For adults only. Do not exceed the recommended daily dose. If you are pregnant, consult your doctor or midwife before taking this supplement. This product is not a substitute for a varied, balanced diet and a healthy lifestyle.
This content is for information purposes only and is not a substitute for advice from a healthcare professional.
