Vitamin D and Irritable Bowel Syndrome: a causative link?
A recent study by the University of Sheffield in England has created waves in the media by associating Irritable Bowel Syndrome (IBS) with vitamin D deficiency. Let me separate fact from fiction here and give you some tips to ensure that you get the maximum vitamin D in your diet.
An advance in the research on Irritable Bowel Syndrome
It is well known that, as compared to the general population, a larger proportion of people with Irritable Bowel Syndrome has a vitamin D deficiency (Khayyat, 2015). What we were not aware of until now, it is that vitamin D probably plays a role in the quality of life and symptom management among individuals with IBS.
The study, published in December 2015 in the British Journal of Medicine, gathered together 51 patients, all of whom were diagnosed with IBS, but were otherwise healthy. The purpose of the study was to determine whether patients who initially had below average serum levels (concentration in blood) of vitamin D, would benefit from supplementation. The study also wanted to determine whether having low serum levels of vitamins influences the quality of life among patients.
The results obtained by the research team are significant in some respects but inconclusive in others. Indeed, it has been shown that a deficiency in vitamin D was associated with a lower quality of life among people diagnosed with IBS. On the other hand, vitamin D supplementation did not improve the participants’ quality of life.
So was it a wasted effort? Luckily not! A possible link between vitamin D supplementation and an improvement in the quality of life has not yet been established. Nevertheless, a few clinical cases do reveal that some people see a marked improvement after starting to take vitamin D supplements. Studies with a larger population and over longer period of time will allow us to better understand the link between vitamin D and IBS.
Which foods are rich in vitamin D?
Even if no link has yet been established between the quality of life in patients with IBS and vitamin D, it’s still worth having a vitamin D-rich diet! It becomes all the more important during this time of year, when we are not sufficiently exposed to the sun’s UVB rays to synthesize vitamin D by ourselves. Indeed, in the winter months (October to March), we find it almost impossible to synthesize vitamin D, even if we are exposed to the sun.
Vitamin D plays an important role in the absorption of calcium and phosphorus, in the proper functioning of the immune system and in reducing the risks of developing certain cancers and chronic diseases.
The best sources of vitamin D in the diet are milk and vegetable-based drinks fortified with vitamin D, egg yolks and some fatty fish like salmon, snapper and mackerel. Certain foods like margarine and orange juice are also fortified with vitamin D in Canada.
Here are a few of our recipes that are good sources of Vitamin D:
- Energizer Breakfast Bowl
- Clam Chowder… with mussels!
- Mushroom Risotto
- Fusilli with Tuna
- Mango and Lime Mousse
In conclusion, some people with IBS may probably benefit from a vitamin D supplement; studies in the coming years will no doubt enable us to know why and what the optimal doses are to restore a good quality of life. For now, make sure that your diet meets the recommendations for vitamin D, as is the case in low FODMAP meal plans for irritable bowels and in all other meal plans as well.
If you are over 50 years, you should take a vitamin D supplement of 600 IU, and a supplement of 800 IU if you are over 70 years. If you are not sure that your diet sufficiently meets your vitamin D requirements, you can measure your serum levels during a blood test. The results will help your physician or dietitian to determine whether a supplement is needed.
Dietitians of Canada. (25 février 2014). Sources of Vitamin D. Retrieved from http://www.dietitians.ca/Your-Health/Nutrition-A-Z/Vitamins/Food-Sources-of-Vitamin-D.aspx
Khayyat, Y., & Attar, S. (2015). Vitamin D Deficiency in Patients with Irritable Bowel Syndrome: Does it Exist? Oman Medical Journal, 30(2), 115–118. http://doi.org/10.5001/omj.2015.25
Tazzyman, S., Richards, N., Trueman, A. R., Evans, A. L., Grant, V. A., Garaiova, I., … Corfe, B. M. (2015). Vitamin D associates with improved quality of life in participants with irritable bowel syndrome: outcomes from a pilot trial. BMJ Open Gastroenterology, 2(1), e000052. http://doi.org/10.1136/bmjgast-2015-000052