Vitamin D and IBS

We hear a lot about the importance of vitamin D with respect to its links to mood, bone health, immunity and hormonal regulation, but did you know it also plays an important role in gut health? This is not surprising if you consider there are special vitamin D receptors in the gut and most absorption occurs in the intestines. Studies on this topic are relatively new and are ongoing, however recent research shows that vitamin D deficiency is proportionately high among people with irritable bowel syndrome (IBS), and that vitamin D has reduced the severity of IBS symptoms for some. A key factor in this relationship may be the role of vitamin D in mitigating inflammatory influences in the lining of the intestinal tract. This may explain the relationship between gut sensitivity and pain perception in IBS. If you have been diagnosed with IBS, or if you habitually experience disruptions in the regularity of your stool form, it may be helpful to consider Vitamin D.

IBS is a long-term health condition affecting around 12% of the US population, primarily women. Those with IBS typically experience stomach cramps, abdominal bloating, and pain with diarrhea and/or constipation. These symptoms can create feelings of emotional distress, and commonly interfere with social or work demands and may result in avoidance strategies. The cause of IBS is not precisely understood, however symptoms are often triggered by certain foods as well as life stressors. Symptoms can come and go over the course of years, and many never find a permanent cure. Some physicians prescribe antibiotics, antispasmodics or antidepressants, but these approaches do not necessarily address an underlying cause. In truth, Vitamin D is just part of the whole picture, but it can be a key component in a treatment program that helps relieve symptoms with a helpful hand rather than a harsh one. It deserves a closer look. 

Vitamin D

By some estimates, nearly half the US population is low in vitamin D according to current standards, especially older adults, young women, infants and individuals with darker skin tones. Vitamin D is a fat-soluble vitamin that exists in two forms, D2 and D3, with the latter being much more effective at raising blood levels of vitamin D. Vitamin D3 is actually a steroidal hormone precursor that’s made by the body when the cholesterol in skin is exposed to the UV rays of the sun. Vitamin D3 is also obtained through the diet. Small amounts of vitamin D3 can be found in a number of foods, with the most significant sources including wild-caught, cold water oily fish such as salmon, herring, mackerel and tuna. Even the richest food sources require daily consumption to maintain consistent vitamin levels. Without supplementation, it’s possible our vitamin D3 needs may be met as a result of sunlight exposure, however this is highly variable and for the majority of folks who spend most of their days indoors, this may not be enough, particularly through the winter months. In short, supplements are often a good solution for most of us. 

How much do you need?

Symptoms of vitamin D deficiency (typically below 30 ng/mL) are non-specific, including fatigue, altered mood, insomnia, joint pain, muscle weakness and hair loss—although levels on the low end of the normal range may well benefit from a boost. Normal blood levels of vitamin D3 fall within a rather wide range of 30 to 100ng/mL, with 30 being the minimum to avoid deleterious effects. However, levels don’t have to be below 30 to be considered sub-optimal, and many experts consider 60–70 to be more beneficial. As important as it is for us to have adequate vitamin D, it’s equally important to not over-do it. A blood level above 125 is considered toxic and can cause a number of adverse side effects, including raising blood calcium concentrations. 

While most people are likely to fall within normal range, you may want to check your vitamin D level if you have reasons to suspect they may be sub-optimal. The best way to know for sure if you are lacking in vitamin D3 is through a simple blood test. Once a target serum level of D3 is obtained, it can be maintained with daily intake of 800–1000 IU (equivalent to 20–25mcg), either through diet, supplementation, sun exposure, or a combination. Bear in mind that vitamin D absorption process can be inhibited by the effects of menopause or hormone therapy that affects estrogen levels, such as IVF.

When it comes to IBS, there is no silver bullet and treatment can take time but many things can manage symptoms and lessen severity. Vitamin D3 can play a promising role, along with other modalities such as acupuncture, medicinal herbs and nutritional therapy. 

References

Abbasnezhad, A., Amani, R., Hajiani, E., Alavinejad, P., Cheraghian, B., & Ghadiri, A. (2016). Effect of vitamin D on gastrointestinal symptoms and health-related quality of life in irritable bowel syndrome patients: a randomized double-blind clinical trial. Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 28(10), 1533–1544. https://doi.org/10.1111/nmo.12851

El Amrousy, D., Hassan, S., El Ashry, H., Yousef, M., & Hodeib, H. (2018). Vitamin D supplementation in adolescents with irritable bowel syndrome: Is it useful? A randomized controlled trial. Saudi journal of gastroenterology : official journal of the Saudi Gastroenterology Association, 24(2), 109–114. https://doi.org/10.4103/sjg.SJG_438_17

Gonzalez, C. (2010). Vitamin D Supplementation: An Update. US Pharmacist, 35(10), 58–76. 

Jalili, M., Vahedi, H., Poustchi, H., & Hekmatdoost, A. (2019). Effects of Vitamin D Supplementation in Patients with Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. International journal of preventive medicine, 10, 16. https://doi.org/10.4103/ijpvm.IJPVM_512_17

Khan, Q. J., & Fabian, C. J. (2010). How I treat vitamin d deficiency. Journal of oncology practice, 6(2), 97–101. https://doi.org/10.1200/JOP.091087