Research Update: Occurrence of Micronutrient Deficiencies in IBS

Micronutrient July 2022.png

Chloe Swiney - Research Dietitian, 21 July 2022

Due to the unpleasant symptoms caused by foods, IBS sufferers tend to highly modify their dietary intake to find some sort of relief.1 However, through this process, IBS sufferers may unknowingly expose themselves to deficiencies in a range of nutrients.(1)

A systematic review released this year compared the deficiencies in micronutrients seen from the usual diet of those with IBS, as well as whilst on restrictive diets used to control IBS symptoms.(1)

First, let’s understand what micronutrients are. Performing a large range of important functions within our body, micronutrient is an overarching term for vitamins, minerals and trace elements.

Micronutrient Table 1

The majority of these micronutrients cannot be produced by the body so it is essential to get them from our diet.1 They are found in a broad range of foods, especially fruits, vegetables and animal products such as meat, eggs and dairy.(2)

The systematic review by Bek et al found that IBS patients' usual diets were significantly low in vitamins B1, B2, B6, B9, calcium, iron, magnesium and zinc when compared to the UK and US recommended intakes.(1) When compared to healthy control, IBS patients were again found to have reduced consumption of vitamin A, B2, B9, B12, calcium and zinc.(1) 

They also looked at those with IBS consuming special symptom management diets including low FODMAP, modified National Institute for Health and Care Excellence guidelines (mNICE), and the Specific Carbohydrate Diet (SCD).(1) They found that those consuming the low FODMAP diet had a lower intake of vitamins B1, B2, B9, calcium, iron and magnesium.(1) Those on the mNICE diet had lower calcium intake, and the SCD consumers had lower vitamin B9 and D consumption.(1) 

The reduced consumption of these specific micronutrients in both usual IBS diets and specialised symptom reduction diets may be caused by the fact that these vitamins and minerals are often found in foods such as cereals, beans and dairy products that trigger symptoms in those with IBS.

This data shows us two key things:

  1. Dietary support from a trained dietitian is essential for both symptom management in IBS and also in achieving nutritional adequacy
  2. The elimination phase of a low FODMAP diet is not intended for long-term use, and it is crucial that you work with a trained dietitian to learn when foods trigger your symptoms in order to reintroduce them and aim for adequate micronutrient consumption.

One way to avoid possible micronutrient deficiencies is substituting high FODMAP foods for nutritionally equivalent low FODMAP alternatives. Check out this graphic on some simple swaps for like foods:


There are also some great low FODMAP foods containing these key nutrients listed in table 2.

Micronutrient Table 2

Are you concerned about your nutrient consumption or have been trying to tackle IBS and the low FODMAP diet alone? You can find a list of Monash FODMAP trained dietitians on our dietitians directory in the app or on our website who can support your nutritional needs: 


  1. Bek S, Teo YN, Tan XH, Fan KHR, Siah KTH. Association between irritable bowel syndrome and micronutrients: A systematic review [published online ahead of print, 2022 May 17]. J Gastroenterol Hepatol. 2022;10.1111/jgh.15891.
  2. Vitamins and minerals - Better Health Channel. Published 2022. Accessed July 14, 2022.
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