Wondering if Your Vitamin D Supplement May Cause Changes in Your Bowel Movements? Your Questions Answered

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    Some have claimed that vitamin D causes occasional constipation. Is this fact or fiction? Read on to learn the answer.

    What role does vitamin D play in your body?

    Vitamin D, sometimes called “the sunshine vitamin,” is a fat-soluble vitamin that helps the body retain calcium and phosphorus, both of which are crucial for building bone. Vitamin D has also been shown to be a supporter of immune health. There are two forms of vitamin D: D2 (ergocalciferol) and D3 (cholecalciferol). Both forms occur naturally when the skin is exposed to the sun’s ultraviolet-B (UV-B) rays. D2 is present in plants and D3 is present in animals; some foods are also fortified with vitamin D. Vitamin D deficiencies are surprisingly common, affecting almost half of the U.S. population.

    Because of the presence of vitamin D receptors throughout the body, some theorize that vitamin D plays a role in health beyond bone and immune health.

    How does vitamin D affect your stomach?

    Vitamin D can affect your stomach in a number of ways. One reason for this is that vitamin D and its nuclear receptor (VDR) have been shown to regulate the integrity of the intestinal barrier. Metabolites from your gut microbiota may also regulate the expression of the VDR.

    Furthermore, vitamin D toxicity can sometimes lead to gastrointestinal discomfort. Toxicity most often occurs when taking vitamin D supplements in large quantities without guidance from a healthcare provider. Studies suggest that doses above 1,000 mcg (40,000 IU) for long periods over a month can lead to toxicity without periodically measuring blood levels. Because the low amount of vitamin D found in food is unlikely to reach a toxic level, and because the skin prevents excess D3 from forming in response to sunlight, you’re unlikely to experience toxicity.

    Does vitamin D cause occasional constipation? What the research says

    If you’re taking vitamin D supplements, you might be concerned about experiencing occasional constipation. Fear not: The connection between vitamin D and constipation is largely a myth. No research to date has demonstrated a direct, causal relationship between vitamin D and constipation. Some studies have found correlations between the presence of digestive issues and lower vitamin D levels; that said, correlation, as we all know, is not the same as causation.

    Can vitamin D cause stomach pain?

    Vitamin D toxicity is rare, but when it does occur, it can indeed result in some stomach pain. That’s especially true if the vitamin D supplement is paired with calcium. Doctors typically recommend not taking vitamin D supplements containing more than 100 mcg (4,000 IU), unless lab results indicate larger doses are needed to quickly boost nutrient status. In some cases, one single large dose of vitamin D can be prescribed by your healthcare provider.

    Can vitamin D cause nausea?

    Like stomach pain, nausea is a possible side effect of vitamin D toxicity.

    Other possible causes of occasional constipation

    Occasional constipation has a number of possible causes related to diet, schedule changes, and traveling.

    First, consider your level of hydration. Some studies have shown that improper hydration can contribute to constipation, with constipation being shown to be caused by fluid restriction. If you’re experiencing dehydration, be sure to up your intake of water. However, increasing your water intake will not improve your stool consistency if you’re already properly hydrated.

    Next, consider your fiber intake. The recommended daily intake of fiber is between 25-38 grams daily. Per this study, fiber intake can support digestive health and support regular bowel movements.

    Lack of physical activity, too, has been linked to constipation, as in this study of Hong Kong adolescents. You should also talk to your doctor about any medications you’re taking, since certain medications can lead to constipation. If you are dealing with chronic constipation, it could be a symptom of something more serious and you should seek assistance from a healthcare provider.

    Natural solutions to occasional constipation

    Fortunately, there are some natural ways to address occasional constipation. It all starts with lifestyle. Make sure you’re eating a nutrient-rich diet, getting enough fruits and veggies. Eat enough fiber, too! You’ll also benefit from staying hydrated, getting some exercise, and getting enough sleep.

    You can also address occasional constipation by focusing on your gut health. Care/of’s Gut Musts package offers top-notch supplements that support the health of your gut microbiome, thereby promoting healthy digestion. The Gut Musts package includes: probiotics to support the microbiome and regulate the digestive system; prebiotics to support gut health, managing bloating and discomfort; chia-flax, to support fiber intake, and digestive enzymes, to ensure proper digestion, helping to relieve gas and indigestion.

    Occasional constipation from time to time due to temporary changes such as traveling, dietary changes, or lack of hydration can be normal however chronic constipation should be discussed with your healthcare provider.

    Does vitamin D have other side effects?

    The most obvious side effect of vitamin D toxicity is a buildup of calcium in the blood, which can lead to stomach problems, fatigue, and frequent urination.

    How much vitamin D should I take per day to avoid side effects?

    To determine how much vitamin D you should take, you should talk to your doctor about checking your levels; a medical professional can help you determine what dose is right for you. The recommended daily allowance of vitamin D for adults is 15 mcg (600 IU); if you’re over 70 years old, the recommendation goes up to 20 mcg (800 IU). For more on vitamin D dosages, check out this in-depth explainer from Care/of.

    How to get more vitamin D

    Vitamin D is available in a wide variety of food sources. Check out this Care/of article to learn about some foods especially rich in vitamin D.

    Vitamin D is also available in supplement form, both as a prescription and an over-the-counter supplement. Buying a vitamin D from a tested, reputable supplement brand is a good way to make sure that you’re getting the best quality available.

    Considering a vitamin D supplement?

    If you are, you might want try out Care/of’s vitamin D supplement. This easy-to-digest supplement comes in 30 day supplies and has been shown to support calcium absorption and bone health. And, as discussed above, it won’t cause constipation!

    Key takeaways

    Vitamin D is a fat-soluble vitamin that supports bone health and immune health, among other important bodily functions. While vitamin D toxicity can sometimes lead to stomach pain, vitamin D itself has not been shown to lead to constipation. Suggestions to the contrary are rooted in myth, not in the available science. If you are experiencing any chronic health issues always be sure to discuss your concerns with your doctor to create the best plan unique to your needs.

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    Dr. Carla Montrond Correia ND, CNS
    Medical Content Manager
    Dr. Montrond-Correia is a licensed naturopathic physician and a certified nutrition specialist (CNS). She holds degrees from University of Bridgeport, Georgetown University, and University of Saint Joseph, and supplemented her education with internships in the health and wellness space. She's focused on research, herbal medicine, nutrigenomics, and integrative and functional medicine. She makes time for exercise, artistic activities, and enjoying delicious food.
    Our Editorial Staff
    Freelance Contributor
    The Care/of Editorial Team is made up of writers, experts, and health enthusiasts, all dedicated to giving you the information you need today. Our team is here to answer your biggest wellness questions, read the studies for you, and introduce you to your new favorite product, staying up to date on the latest research, trends, and science. Each article is written by one of our experts, reviewed both for editorial standards by an editor and medical standards by one of our naturopathic doctors, and updated regularly as new information becomes available.