Multivitamins on a low FODMAP diet

Multivitamins and IBS

Dakota Rhys-Jones - Research Dietitian, 22 July 2020

There is no doubt that health and wellness industries have thrived over the last decade, with the global dietary supplement market valued at US$106 billion in 2018 (1). Over a third of Australians and half of Americans reportedly use dietary supplements and consumers across the globe are hungry for the next best product that will optimise their health or prevent chronic diseases (2, 3). For those following a low FODMAP diet, multivitamins may seem fitting due to dietary restrictions, however, not always necessary. This leads us to ask - what are the role of multivitamins in IBS?

Multivitamins and nutritional adequacy of a low FODMAP diet

Both the Australian and American Dietary Guidelines suggest that supplement use is only needed for certain subgroups of the population, because meeting nutritional requirements should be achieved through food sources alone (4, 5). Interestingly, in Australia, those who take supplements are better educated, exercise more and meet fruit/vegetable guidelines compared to those who don’t take supplements (3). Meaning many individuals who take these supplements probably don’t even need to be in the first place. Multivitamins are only relevant for those individuals whose diets are already deficient in certain nutrients, whether they have IBS or not.

Questions are often raised over the nutritional adequacy of a low FODMAP diet, particularly in terms of calcium and fibre intake. Fibre is not usually found in multivitamins, but of course, is of interest and importance for those following a low FODMAP diet. Interestingly, both calcium and fibre are widely under consumed in the general population, and research suggests that the low FODMAP diet doesn’t significantly impact on nutrition adequacy compared to regular diets (6, 7). Additionally, the elimination phase of the diet is only intended for the short term (2-6 weeks), and greater flexibility and variety of nutrients is encouraged in the personalisation phase of the low FODMAP diet. 

Role of a dietitian

The role of a dietitian is integral to the success of symptom reduction for people with IBS (7, 8). A dietitian’s specialised skillset can determine which nutrient targets are being met or not, and whether supplementation is necessary. Particular population groups might be at a higher risk of deficiencies than others while following a low FODMAP diet, and it is important for these groups to work closely with an experienced dietitian. For example, children/adolescents or the elderly who have increased nutrient needs, or those with disordered eating patterns, in which a restricted diet may exacerbate these behaviours (9, 10). 

Dietary supplements - what to look out for while on a low FODMAP diet

If you are recommended to or decide to take a supplement, here are some factors to consider. Firstly, some FODMAPs can be hidden in the ingredients e.g. inulins, lactose or polyols. Be sure to check the ingredients panel carefully before selecting any nutritional supplement. Secondly, some multivitamins will have over 100% of the recommended intakes for nutrients, is this an issue? The answer is not that simple and depends on the nutrient in question. For example, supplements containing an excess of iron or magnesium are known to cause gastrointestinal upset, while for others, like vitamin B12, high doses are not toxic and show no side effects (11). Nutrients behave differently when in food compared to supplements, and almost all clinical problems related to an excess of nutrients are associated with supplements, not food (4).

For those looking to play it safe, the Monash FODMAP app now has a ‘dietary supplements’ category, which has a range of low FODMAP certified products, including multivitamins. Overall, our best suggestion is to work with your health professional, rather than self-diagnosing nutritional deficiencies, as they will work out what is best for you! 


1.            Deloitte. Responsible nutrition - the opportunity for FMCGs & retailers: Deloitte; June 2019 [15/07/2020]. Available from:

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3.            Burnett AJ, Livingstone KM, Woods JL, McNaughton SA. Dietary Supplement Use among Australian Adults: Findings from the 2011-2012 National Nutrition and Physical Activity Survey. Nutrients. 2017;9(11):1248.

4.            National Health and Medical Research Council. Eat for Health Educator Guide. Canberra: NHMRC; 2013.

5.            U.S. Department of Health and Human Services and U.S. Department of Agriculture. Dietary Guidelines for Americans. 2015-2020 December 2015.

6.            O'Keeffe M, Jansen C, Martin L, Williams M, Seamark L, Staudacher HM, et al. Long-term impact of the low-FODMAP diet on gastrointestinal symptoms, dietary intake, patient acceptability, and healthcare utilization in irritable bowel syndrome. Neurogastroenterol Motil. 2018;30(1).

7.            Staudacher HM, Ralph FSE, Irving PM, Whelan K, Lomer MCE. Nutrient Intake, Diet Quality, and Diet Diversity in Irritable Bowel Syndrome and the Impact of the Low FODMAP Diet. Journal of the Academy of Nutrition and Dietetics. 2020;120(4):535-47.

8.            Tuck CJ, Reed DE, Muir JG, Vanner SJ. Implementation of the low FODMAP diet in functional gastrointestinal symptoms: A real-world experience. Neurogastroenterology & Motility. 2020;32(1):e13730.

9.            Hill P, Muir JG, Gibson PR. Controversies and Recent Developments of the Low-FODMAP Diet. Gastroenterol Hepatol (N Y). 2017;13(1):36-45.

10.          Chumpitazi BP, Cope JL, Hollister EB, Tsai CM, McMeans AR, Luna RA, et al. Randomised clinical trial: gut microbiome biomarkers are associated with clinical response to a low FODMAP diet in children with the irritable bowel syndrome. Aliment Pharmacol Ther. 2015;42(4):418-27.

11.          Mulholland CA, Benford DJ. What is known about the safety of multivitamin-multimineral supplements for the generally healthy population? Theoretical basis for harm. The American Journal of Clinical Nutrition. 2007;85(1):318S-22S.

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