Your Vitamin D Supplement May Be Why You're Gassy and Bloated

Vitamin D is one of those essential nutrients everyone always seems to be talking about. While it's a fat-soluble vitamin the body produces when exposed to the sun — which explains why it's commonly referred to as the "sunshine vitamin" — it's estimated that nearly 1 in 4 Americans don't get enough vitamin D for optimal health, according to the Office of Dietary Supplements (ODS).

Many people get their daily dose via vitamin D supplements, and taking the proper dose — which is 600 IUs, per the ODS — is deemed "generally safe" by the Mayo Clinic. However, there's some thought vitamin D supplements may lead to a distended belly.

Exceeding the recommended daily allowance of vitamin D for an extended period of time can bring about some unpleasant side effects. "Because vitamin D is fat-soluble, your body stores the excess — and this can lead to toxicity if you take too much of it," Angie Kuhn, RDN, director of research and nutrition at Persona Nutrition, tells LIVESTRONG.com.

She adds that vitamin D overload may lead to bloating and gas associated with constipation, diarrhea, upset stomach and other intestinal issues. Getting too much vitamin D also increases how your body absorbs calcium, and excess calcium can contribute to digestive symptoms like nausea and vomiting too, according to the ODS.

FYI: Toxic amounts of vitamin D may also cause weakness, frequent urination and unexplained weight loss, along with damage to the heart, kidneys and blood vessels.

The best way to determine your current level of vitamin D is through a blood test, according to the ODS. Levels 50 nmol/L (nanomoles per liter) and higher are considered sufficient for most adults. Anything over 125 nmol/L is likely to be toxic while levels under 30 nmol/L can indicate a deficiency.

This vitamin is necessary for multiple health benefits, such as building and maintaining strong bones and encouraging the absorption of calcium, a mineral that also contributes to bone health and helps with muscle function and nerve transmission.

"Vitamin D is also known to assist with digestive health, and it has anti-inflammatory and immune-modulating effects, so those deficient in this vitamin are more susceptible to infection," Kuhn says.

In fact, there's a high prevalence of vitamin D deficiency among people with irritable bowel syndrome (IBS), according to a January 2018 study in the ‌European Journal of Clinical Nutrition‌. While additional research is required, these initial findings suggest vitamin D supplements may help relieve some of the common symptoms associated with IBS, such as constipation, diarrhea, bloating and abdominal pain.

Vitamin D may be best known for its vital role in bone health, but it's also important for maintaining, as well as restoring, gut health. So while getting enough of this vitamin can help keep chronic gas and bloating at bay, too much vitamin D can lead to digestive difficulties that may result in gas and bloating.

Keep in mind it's unlikely you'd reach toxic levels of vitamin D from food and sunshine alone. According to the ODS, vitamin D toxicity is more likely due to taking supplements with high amounts of the nutrient or excessive use of tanning beds.