Can the "sunshine vitamin" help with irritable bowel syndrome?
Updated: Sep 4
The "sunshine vitamin", or Vitamin D, has been a super star vitamin in the spotlight lately. Deficiency of this vitamin has been implicated in promoting progression of cancer (1), obesity (2), mood disorders/PMS (3,4), osteoporosis (5) and so much more! Given that over one billion people are vitamin d deficient worldwide. Risk for deficiency of this vitamin increases when a person (a) does not spend enough time outdoors/in the sun and/or lives in a place of higher latitude, (b) does not consume vitamin-d containing foods (fortified milk/milk alternative products, eggs, fish), (3) is older age, (4) is female or (5) has darker skin (6).
So if deficiency of this vitamin is associated with so many chronic conditions, can vitamin d help with irritable bowel syndrome?
Recent research says there's a good chance! First of all, one study found 82% of those studied with diagnosed IBS (small sample size- 42 patients with vitamin d deficiency out of 60) were deficient in vitamin d. I will note that the population in this study was mostly female (which we know are at a higher risk for vitamin d deficiency) and the average vitamin d level for all participants was actually on the lower side as well, though not considered deficient (31 for healthy, 21 for IBS). Despite this, the fact that there was a statistical difference between IBS participants and healthy controls suggests it's certainly worth checking your vitamin d levels if you suffer from irritable bowel syndrome (7). Another study (this one was a "gold standard" randomized, double-blind clinical trial) showed significant improvement in reported IBS symptoms and quality of life in participants who received 50,000 IU vitamin d every 2 weeks for 6 months (8).
Some researchers believe vitamin d plays a role in fighting inflammation and modulating the immune response in a favorable way in the body (9) and this is believed to be why vitamin d may help with irritable bowel syndome symptoms/overall quality of life. Another interesting take on how vitamin d can help irritable bowel syndrome is that deficiency of this vitamin actually causes changes to our microbiome (the environment in our gut that is made up of a balance of bacteria and yeast). When these changes take place, our gut may not produce enough pantothenic acid (a B vitamin that is not actually found in food- it's only produced in our gut) which can then actually promote an inflammatory state in the body. This particular study was done on neurology patients but did find that supplementation of a combination of vitamin D and a B complex improved sleep, reduced pain and "unexpectedly" resolved "bowel complaints" (lucky for those guys, right?) (10).
Need more convincing to get your vitamin d levels checked? If you are in the special group of people who happen to have both acne and irritable bowel syndrome (let me just say you are NOT alone! I see this all the time!)- one study did find that vitamin d helped stop the reproduction of those pesky bacteria we know to cause acne called P. acnes (11). While more research is needed to determine if supplementing vitamin D can help acne, I certainly make sure to get my acne clients vitamin b and vitamin d levels checked for this reason!
So, what is the normal vitamin D level range?
First of all, we know that the 25(OH) vitamin D is the best test to reflect overall vitamin d status, so this is the test I'll be using for the following ranges. 30 nmol/L or less is considered deficient (although, if I have a patient that tests less than 35 nmol/L, depending on the situation and especially if this value was taken during the summer months, I usually recommend a low dose vitamin d supplement anyway if there are no contraindications for that patient). While 30-50 nmol/L is not considered deficient, it is not considered "optimal" for bone/overall health in healthy people. So ideally, I like to see my patient's vitamin d levels above 50 nmol/L. If the level is above 125 nmol/L, some research indicates negative effects, so this is not recommended (12).
What should I do if I DO have low or sub-optimal vitamin d level?
First and foremost check with your doctor or knowledgeable health practitioner. There are risks to taking supplements without guidance such as the risk of contamination of the supplement/lack of quality and/or improper dosing or contraindications with medications/other supplements. Typically, with my patients suffering from both gut issues AND acne or other skin issues, I recommend a high quality vitamin d supplement if levels are less than 35-40 (if 35-50 in some patients I might just recommend 20 minutes of direct sunlight every day!).
As much credit as this mighty vitamin has been getting recently, it likely won't be the "end-all, be-all" to gut issues and/or acne (although research shows us it might help!)- in my practice, I always choose to look at the individual as a whole. I look at what systems may be effecting others and producing symptoms like irritable bowel syndrome, acne, eczema, congestion, etc. This means I focus on getting to the root cause of the issue and some other therapies I might recommend include changing diet, managing stress and improving sleep.
I would love to hear what you think about this article and more topics you'd like to learn about. Leave a comment or connect with me on social media! I'm @acne.nutritionist on Instagram
If you are ready to "cut to the chase" and minimize trial-and-error to find the root causes of your irritable bowel syndrome, leaky gut, candida, acne, eczema, psoriasis or SIBO, schedule a free consultation with me.