Activity 4 Maternal supplements (McGuire). An evidence-based approach to maternal nutrient supplementation during lactation (15-20 mins)

A wholesome and varied diet is fundamental to health

Postpartum nutrition is an important consideration during breastfeeding for both mother and baby. While it is desirable that nutrition is supported by a healthy and varied diet, supplementation may be required in some cases for the health of both the mother and the infant.27

Micronutrients and deficiency

Micronutrient deficiencies are also not always visible and have been referred to as ‘hidden hunger’.27

Micronutrient deficiency affects nearly one-third of the population worldwide, with incidence concentrated primarily in low- and middle-income countries.18,28 It also remains an issue among breastfeeding mothers and their infants in high-income settings, particularly among women who avoid meat and/or milk.18

This is also true for women who lack sufficient supplies of vitamin B12 and vitamin D, and/or women who are iron deficient.18 Key causes of inadequate maternal nutrition include:

• Rapid weight loss

• Restrictive diets +/- excessive exercise

• Eating disorders / larger body

• Bariatric surgery

• Malabsorption syndromes e.g. inflammatory bowel disease.

In the absence of a healthy or varied diet, or where deficiency exists, multiple micronutrient maternal supplementation may be suggested. However, evidence for supplementation in lactation is scarce.18 Additionally, it is unclear to what extent low intakes of micronutrients affect the success of lactation, infant outcomes, or maternal health, in the absence of distinct nutritional deficiency in the infant.

Most published studies compared either individual micronutrient levels in maternal plasma and breast milk or assessed the value of supplementation to correct a micronutrient deficiency, rather than studying maternal and infant outcomes.

• A 2016 Cochrane review remains the most comprehensive assessment of this topic.18 Only two small studies were deemed appropriate for inclusion, one from Brazil and one from the USA and included women who had low socioeconomic status. Primary outcomes were maternal morbidity, infant morbidity, and adverse effects of micronutrients within three days of receiving the supplement. The authors determined the included studies to be poorly described and did not report on outcomes of interest.

• A more focused systematic review, published in 2021, aimed to assess evidence for an association between breast milk micronutrients and infant neurodevelopmental outcomes.29 This review retrieved only three observational studies that assessed associations between breast milk levels of vitamin B6, carotenoids, or selenium and infant development. The authors were unable to establish relationships between these breast milk micronutrients and infant neurocognitive due to the low number and quality of studies.

Authors of both systematic reviews concluded that further research is required to determine the benefit of multiple-micronutrient supplementation during lactation.

Rapid maternal weight loss during breastfeeding

While postpartum weight retention contributes to women’s weight trajectories over their lifespan, it is unrealistic to expect a rapid return to their pre-gravid weight. The media, particularly social media, have created an abnormal expectation that women lose weight ‘fast’ rather than ‘smart’ postpartum.

Negative self-image can not only contribute to inappropriate dietary restraint but also unhealthy eating behaviours, psychological distress, and postpartum depression. Harder and colleagues34 found the risk of maternal obesity is reduced by 4% for each month of breastfeeding, with the effect lasting for up to 9 months of breastfeeding.

Strategy:

• Promote breastfeeding as a strategy for healthy maternal weight loss.

• The basic principles of healthy eating remain the same for all adults, including women who are breastfeeding. However, women at higher risk of micronutrient deficiencies may require more specialised support, with a referral to the woman’s GP or a dietician to discuss the risk of micronutrient deficiencies.

Restrictive diets and breastfeeding

In breastfeeding women following a strict vegetarian or vegan diet, there have been reports of vitamin B12 (cobalamin) deficiency in the fully breastfed infant.

Infant symptoms may present as failure to thrive, developmental delay, and/or haematologic abnormalities, and usually manifest between 4-8 months of age.33

Strategy:

• Increase intake of plant foods fortified with cobalamin, e.g. cereals, soy/ rice beverages, yeast

• Refer to the woman’s GP for vitamin B12 deficiency screening.

• General advice should include increased maternal and infant intake of plant foods fortified with cobalamin, such as cereals, soy/rice beverages, yeast and/or the potential for supplementation e.g. vitamin B12 (1000 µg/day).33

Bariatric surgery and lactation

Women may become pregnant, and subsequently breastfeed, after weight loss associated with bariatric surgery. Along with substantial weight loss, bariatric surgery is associated with malabsorption of essential vitamins, minerals, and drugs.35

To prevent maternal malnutrition, evidence-based guidelines recommend daily multivitamin supplements following bariatric surgery, based on surgery type. 35,36

Adverse infant outcomes have been reported in pregnant and postpartum women after bariatric surgery in a 2015 systematic review. While data was drawn from only 17 case reports and 8 small cohort studies, the most common adverse neonatal outcomes related to maternal micronutrient deficiencies: visual complications (vitamin A deficiency), intracranial haemorrhage (phylloquinone), neurological & developmental impairment (vitamin B12), and neural tube defects (folate).33 This led the study authors to recommend micronutrient screening at 6-8 weeks postpartum for breastfeeding mothers.37

Despite this research, a 2022 systematic review is the first to assess the impact of bariatric surgery specifically on breastfeeding.38 Eleven observational studies were identified. The investigated observed increased nutrient needs during pregnancy and lactation for this cohort. However, they concluded that breast milk is adequate in nutrients in women who have undergone bariatric surgery. So, breastfeeding is not contraindicated, as long as there is screening and correction to identified nutrient deficiencies in both child and mother, supported by nutrition counselling.

Strategy:

• Micronutrient screening 6-8 weeks postpartum for breastfeeding women who have undergone bariatric surgery preconception.

Recommended resources

The role of vitamin supplementation during lactation (including indications for multivitamins; recommendations for patients who eat plant-based diets)

'Intuitive eating' in the perinatal period

What does the research tell us about larger bodied women and breastfeeding? Dr Kate Rassie 11 March 2025

Impact of maternal breast development, diet and diabetes on milk production and composition. Video presentation by Professor Donna Geddes 26 November 2024

References

27. Bailey RL, West Jr KP, Black RE. The epidemiology of global micronutrient deficiencies. Ann Nutr Metab 2015;66(suppl 2):22-33.

28. Keats EC, Das JK, Salam RA, Lassi ZS, Imdad A, Black RE,et al. Effective interventions to address maternal and child malnutrition: an update of the evidence. Lancet Child Adolesc Health. 2021;5(5):367-84.

29. Lockyer F, McCann S, Moore SE. Breast milk micronutrients and infant neurodevelopmental outcomes: a systematic review. Nutrients 2021;13(11):3848.

30. Hollis BW, Roos BA, Draper HH, Lambert PW. Vitamin D and its metabolites in human and bovine milk. J Nutr. 1981;111(7):1240-8.

31. American Academy of Pediatrics. Sun safety and protection tips. Available at: https://www.healthychildren.org/English/safety-prevention/at-play/Pages/Sun-Safety-and-Protection-Tips.aspx. Accessed April 22, 2022.

32. Paxton GA, Teale GR, Nowson CA, Mason RS, McGrath JJ, Thompson MJ. Vitamin D and health in pregnancy, infants, children and adolescents in Australia and New Zealand: a position statement. Med J Aust. 2013 Feb 18;198(3):142-3.

33. Beluska-Turkan K, Korczak R, Hartell B, Moskal K, Maukonen J, Alexander DE, et al. Nutritional gaps and supplementation in the First 1000 Days. Nutrients 2019;11(12):2891.

34. Harder T, et al. Duration of breastfeeding and risk of overweight: a meta-analysis. Amer J Epidemiol 2005; 162: 397-403.

35. Sawaya RA, Jaffe J, Friedenberg L, Friedenberg FK. Vitamin, mineral, and drug absorption following bariatric surgery. Curr Drug Metab 2012; 13(9):1345-55.

36. Parrott J, Frank L, Rabena R, Craggs-Dino L, Isom KA, Greiman L. American Society for Metabolic and Bariatric Surgery integrated health nutritional guidelines for the surgical weight loss patients 2016 update: micronutrients. Surg Obes Relat Dis 2017;13(5):727-41.

37. Jans G, Matthys C, Bogaerts A, Lannoo M, Verhaeghe J, Van der Schueren B, et al. Maternal micronutrient deficiencies and related adverse neonatal outcomes after bariatric surgery: a systematic review. Adv Nutr. 2015;6(4):420-9.

38. Adsit J, Hewlings SJ. Impact of bariatric surgery on breastfeeding: a systematic review. Surg Obes Relat Dis. 2022;18(1):117-22.