Vitamin D and IBD
Now the days are becoming shorter and winter is just around the corner, it is time to consider supporting our Vitamin D intake with supplements, particularly if you have IBD.
Firstly, what is vitamin D and where is it found?
Vitamin D is actually not a vitamin at all, but a hormone which is made in the skin when it’s exposed to sunlight. It is then transported to other areas of the body where it has multiple effects. During the autumn and winter months in the UK (and other northern countries) we are not able to make enough vitamin D from the sunlight and it is important to make up the difference. In addition to making our own Vitamin D, it can be found in foods such as oily fish (mackerel, salmon), eggs and red meat and can be added to products that are fortified like breakfast cereals and milk alternatives. It can be difficult to get the levels of vitamin D we require from food alone, therefore when the sun is not shinning, a supplement is proposed to be the best solution.
Why is vitamin D important?
Vitamin D is needed to help the body absorb calcium and phosphate from our diet, both of which are essential for healthy bones and muscles and can help reduce the risk of soft bones (osteoporosis) and rickets in children.
When taking courses of steroid treatment, it is particularly important to take vitamin D supplements. The British Society of Gastroenterology currently recommends 20ug (800 IU) a day (3), alongside the recommended calcium supplements to increase absorption. This minimises the risk of osteoporosis, which is a significant side effect of steroid treatment.
Recently, the discovery of vitamin D receptors on most cells in the body has renewed interest in the role of vitamin D. It is now believed to be more widely required and there is emerging evidence to suggest it could benefit the heart, help to maintain a balanced mood and most importantly for IBD, help to regulate the immune system (1).
Where is the evidence that vitamin D could be important in IBD?
When we have Inflammatory Bowel Disease such as Crohn’s disease or ulcerative colitis, we are more likely to be deficient in vitamin D than someone without IBD. One study found 63% of Crohn’s disease patients had a vitamin D deficiency (4) which was more than 3 times the national average (6).
Whether or not vitamin D deficiency could be considered a risk factor for the development of Inflammatory Bowel Disease is currently being considered. Equally, it is possible that lower levels of vitamin D could be caused by the disease itself due to malabsorption in the inflamed gut, restricted eating patterns and advice to avoid sunlight when taking certain medications.
A recent review of the main studies on vitamin D supplementation in IBD found that people taking a vitamin D supplement had lower disease activity scores and lower inflammation markers than people with IBD not taking a supplement. The people taking the supplement had higher levels of circulating vitamin D, which was indicative that the supplement was working to increase levels, although the dosage differed significantly between studies (6). This supports the view that vitamin D may have an anti-inflammatory effect.
What are the symptoms of vitamin D deficiency?
Fatigue, bone pain, muscle weakness, aches and cramps, mood changes and depression.
How much should we be taking?
In April 2020, the UK Government issued new advice which encourages all children from the age of 1 year and adults to take a vitamin D supplement of 10 µg (micrograms) a day. This is the equivalent to 400 IU (International Units).
However, there is some discussion around whether recommendations should be higher, particularly for people who have underlying health conditions such as IBD. The safe upper limit for vitamin D is set at 100ug (4000IU), for adults per day (4).
How much vitamin D should I take for IBD?
Although there are no current guidelines for vitamin D supplementation in IBD, there are some studies which indicate a higher amount may be beneficial.
It is recommended that people with Inflammatory Bowel Disease are screened for vitamin D status. Therefore, you should be able to ask your GP or IBD team to test your vitamin D levels, which they can do easily through a blood test. If your levels are particularly low then they will likely recommend treatment with a higher dose until your levels normalise (4).
The amount of vitamin D required is likely to be different depending on where inflammation is present. People with inflammation of the small bowel are thought to require higher doses due to compromised fat absorption and the fat-soluble nature of vitamin D (5).
What type of supplements are available?
Supplements come in two forms D2 and D3. D3 is the type that we get from animal products and is more common in supplements as it is more easily absorbed. D3 is derived from lanolin which is taken from sheep’s wool and is therefore not vegan. However, vegan alternatives from plant-based sources such as lichen are also available.
There are many different type of vitamin D supplements available on the market and it can be very confusing as to which to choose. We may have limited ability to absorb vitamin D in our digestive system, so below are good options for the delivery of vitamin D supplements if you have IBD:
Oral Sprays – the vitamin D is absorbed from the mouth into the blood stream bi-passing the digestive system which may useful for people with malabsorption due to gut inflammation. On the downside these sprays often contain additives such as emulsifiers, preservatives, flavourings and sweeteners to improve the taste.
Liquid Droplets – taken under the tongue and are absorbed in the same way as the mouth sprays. An advantage of the droplets is that you can find brands which only contain the vitamin D on an oil base with no additives.
Gel Capsules – oil-based gel capsules are fast absorbing due to the oil base and easier to digest than standard tablets. These usually only contain vitamin D, an oil carrier and the gelatine capsule.
Can I take too much?
Due to the fact vitamin D is stored in the body, in can be toxic in high concentrations so you should not take more than the safe upper limit of 100ug (4000IU) a day unless your GP/IBD team recommend otherwise. It is best to request a blood test from your IBD team or GP to check your levels before supplementing so we can be sure that you are taking the right amount for you.
Take Away Tips for Vitamin D Supplementation
It is recommended for everyone to take a vitamin D supplement from October through to March of 10ug a day.
People with IBD are more likely to be deficient in vitamin D and can therefore get their vitamin D levels checked by their doctor or IBD team.
Much higher doses of vitamin D may be required to correct any deficiencies but this should only ever be done under the supervision of your IBD team, nutritionist or dietician.
Correcting vitamin D deficiencies may lower inflammation and improve quality of life for people with IBD.
Remember to always check with your GP or IBD team before taking a supplement alongside other medications, as interactions can occur.
If you would like help and support with your IBD, vitamin D support or what dietary and lifestyle changes would be appropriate for you, please get in touch with me. You can book a free call, where I can get to know you, your journey, your struggles, your life, and we can chat about the best route forward for you. You can also ask any questions you have about working with me.
This article was written by Helen Morris (MSc, ANutr) who is our wonderful intern at The NALM Clinic. She's passionate about IBD nutrition research and sharing evidence based IBD nutrition information having lived with Crohn's Disease since 2018.
References
SACN (2016) Vitamin D and Health. Available: https://www.gov.uk/government/publications/sacn-vitamin-d-and-health-report
Baidoun, F (2019) Association Between Vitamin D Deficiency and Inflammatory Bowel Disease. The American Journal of Gastroenterology. 114. S448. doi:10.14309/01.ajg.0000592612.35370.0d
British-Society-of-Gastroenterology Guidelines for osteoporosis in inflammatory bowel disease and coeliac disease 2007 http://www.bsg.org.uk/clinical-guidelines/ibd/guidelines-for-osteoporosis-in-inflammatory-bowel-disease-and-coeliac-disease.html last accessed Oct 2010
Holick, M.F. (1996) Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline, The Journal of Clinical Endocrinology & Metabolism, 96(7) 1911–1930, https://doi.org/10.1210/jc.2011-0385
Guzman-Prado, Y (2020). Vitamin D Therapy in Adults With Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis, Inflammatory Bowel Diseases 26 (12) 1819–1830, https://doi.org/10.1093/ibd/izaa087
National Diet and Nutrition Survey (2016/2017):- https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/772434/NDNS_UK_Y1-9_report.pdf