Evidence backs individual approach to health supplements in pregnancy

New Australian research has added weight to understanding that dietary supplements of vitamins and minerals provide no obvious clinical benefit when taken before or during pregnancy among Australian women who are well nourished.

Reproductive health researchers from the Robinson Research Institute at The University of Adelaide analysed local and international research going back three decades, concluding use of supplements to boost important vitamins and minerals should be dependent on a woman’s ability to meet recommended intakes based on diet alone.

The research was published in the April issue of the Journal of Pharmacy Practice and Research, the flagship journal of the Society of Hospital Pharmacists of Australia (SHPA).

Review author Professor Claire Roberts says the analysis revealed a contrasting assessment of the clinical benefits of single supplements, and supplements packaged together as commercial multivitamins, before and during pregnancy.

‘While routine supplementation of folic acid is well-founded and remains important, supplementation with calcium, zinc and selenium appears to reduce some pregnancy risk factors to varying degrees, while supplementation with vitamin B12, vitamin D and iron is heavily dependent on individual diet and lifestyle.

‘There were also discrepancies across the board in the make-up of four heavily marketed multivitamins and the general recommendations regarding vitamin and mineral supplementation that have been made by the National Health and Medical Research Council (NHMRC) and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists.’

Key nutritional deficiencies have been linked to various complications of pregnancy and birth, including pre-eclampsia, foetal growth restriction, neural tube defects, skeletal deformities and low birthweight.

In one of two related JPPR editorials, Dr Debra Kennedy, Clinical Geneticist from the Royal Hospital for Women in New South Wales flagged concerns of health professionals that more Australian women are avoiding carbohydrates for weight control reasons and gluten-containing foods for non-specific ‘health’ reasons, depriving them of dietary balance.

‘It is concerning that some women take excessive amounts of certain vitamins with no real evidence of need or safety, yet with potential risk of harm – there is a general perception that if something is good, then more of something good must be even better.

‘Unfortunately, this does not always apply to vitamins, high or mega doses of which may not always be as benign as everyone would like to believe.’

Dr Luke Grzeskowiak, Chair of SHPA’s Women’s and Newborn Health Specialty Practice stream says the research highlights that advice regarding supplementation during pregnancy requires an individualised approach and, ideally, the involvement of a pharmacist.

‘This review highlights that, as medicines experts, pharmacists are well-positioned to identify a woman’s individual requirements and factor in other medicines they may be taking, in advising the most appropriate treatment options.

‘For women who have a particularly unhealthy diet or who struggle to eat well due to severe morning sickness, the additional nutrients may be useful however, for the majority of women, complex multivitamin preparations represent an unnecessary added expense.’

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Media coverage

'Pregnancy multivitamin use could harm babies, researchers warn', Herald Sun, 13 May 2018

'Multivitamins a risk to bubs', Herald Sun, 14 May 2018