How vitamin D aids digestive health and improves gut microbiome

01/23/2024

Find out how important vitamin D is so you can build a strong gut microbiome and improve your digestive health.

By Laura Nahins, Registered Dietitian, Nuvance Health

You may know that vitamin D is an important part of your health. Vitamin D helps build strong bones, reduces inflammation in your body and promotes healthy immune function. However, more evidence suggests that vitamin D also greatly benefits your digestive health and improves your gut microbiome.

Find out how vitamin D benefits your digestive health and why you should maintain this easy-to-get nutrient that does so much for your body.

Learn more about the Nuvance Health Digestive Health Institute.

Role of vitamin D in maintaining your gut health

Vitamin D plays a critical role in digestive health by allowing your body to absorb calcium. Calcium is a vital mineral used to build strong bones and teeth. Not having enough vitamin D can make your body unable to absorb calcium, which in return can make your bones weak.

Studies show that vitamin D is more beneficial to your digestive system than previously thought because it helps regulate inflammation inside your gut. Maintaining healthy levels of vitamin D may prove to be very important for individuals who suffer from inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis because of its ability to regulate inflammation.

Sources of Vitamin D and how to increase your levels

Vitamin D is available in a variety of ways including natural or fortified food and from the sun or supplements. Here are a few ways to increase your vitamin D levels to benefit your gut health.
Very few natural foods contain vitamin D, but the ones that do are fatty fish such as trout, salmon, tuna, catfish, sardines, herring and mackerel. In addition to fatty fish, fish liver oils are among the best natural sources of vitamin D.
Other natural vitamin D sources include beef liver, egg yolks and cheese, which all have small amounts of vitamin D. Mushrooms also provide a little vitamin D, and some mushrooms are even exposed to ultraviolet light to increase their vitamin D content.
Fortified foods such as cow’s milk or nut and oat milks have vitamin D added to them. According to the National Institutes of Health, almost all of the U.S. milk supply is fortified with about 3 mcg. of vitamin D per cup. In addition, many plant-based alternatives such as soy milk, almond milk and oat milk are fortified; but foods made from milk, like cheese and ice cream, are usually not fortified. Fortified tofu is another good source of vitamin D and a good way to up your plant-based protein intake. Many cereals are also fortified with vitamin D, just what out for added sugar.
Supplements are a convenient way to boost or maintain vitamin D levels. Vitamin D supplements come in a variety of forms including oral capsules and oils. If you live in the northern hemisphere, it’s a good idea to take a vitamin D supplement at least during the winter months, however, consult your doctor before taking any supplement.
Sun exposure may be the easiest way to receive vitamin D and it’s done through a process called vitamin D synthesis. Vitamin D synthesis occurs when your skin absorbs ultraviolet rays from sunlight. While you may not get enough sunlight depending on where you live, your doctor may recommend taking a supplement or adding certain vitamin D foods to your diet. Speak with your doctor to find out if you are getting enough vitamin D.

Vitamin D and your gut microbiome

Your digestive system is always in contact with the outside world, including different microorganisms such as bacteria, viruses and fungi. Over a lifetime, around 60 tons of food and trillions of microorganisms from the environment go through your digestive system. These microorganisms could affect the health of the gut. Studies show that vitamin D plays a crucial role in maintaining a healthy gut microbiome. Being vitamin D deficient can lead to many health issues and make you more prone to certain autoimmune diseases.

Vitamin D promotes the absorption of calcium in your gut through the intestinal epithelial barrier. Without vitamin D, your gut would not be able to absorb calcium. Your body uses calcium in various ways such as to form healthy bones. Since calcium is vitamin D dependent, it can only be absorbed through the activation of vitamin D. Getting enough vitamin D is important in maintaining proper gut microbiome levels so that your digestive system absorbs calcium.

Learn more about nutrition counseling at Nuvance Health.

Why is your gut microbiome important?

Gut microbiome influences your digestive health by promoting a normal metabolism, ensuring you get adequate nutrition and proper immune function. Your gut microbiome also helps your body make vitamins, absorb nutrients from your food, renew cells in your gut, store fat, keep your gut barrier strong, and even develop your brain function.

Your gut microbiome also helps to break down complex carbohydrates that your body can't digest on its own. These include carbs like resistant starches, which come from cooked, cooled pastas, cellulose, hemicellulose, pectin and gums. Your gut microbiome also breaks down smaller carbs that your body doesn't fully digest, along with sugars and alcohols that you don't absorb from food.

Vitamin D deficiency and digestive disorders

Studies show there is a link between vitamin D deficiency and some digestive disorders. An imbalance of normal gut microbiome is linked to gastrointestinal conditions such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and other diseases such as obesity and type 2 diabetes.

Maintaining optimal vitamin D levels for digestive wellness

Although there is no specific amount of vitamin D you need to maintain your digestive health exclusively, there are recommended amounts that should be present in your body on a consistent basis. According to the National Institutes of Health, people between the ages of 14 and 70 should take 15 micrograms or 600 international units of Vitamin D per day to allow for their cells to perform important functions such as maintaining proper digestive health. Speak with your doctor before taking any vitamin supplement to see if it is right for you.

Find a primary care provider near you.

If you think you are not getting enough vitamin D, talk to your doctor about ordering a blood test. The vitamin D, 25-Hydroxy test is the gold standard when it comes to measuring the amount of vitamin D present in your body. The test results will determine if you have a vitamin D deficiency. Your doctor can talk to you about how to improve your vitamin D levels such as getting more exposure to the sun, including more foods containing vitamin D in your diet or taking a vitamin D supplement. Book your blood draw appointment online.

The bottom line: Vitamin D is a critical part of your nutrition. It helps build strong bones, reduces inflammation in your body and promotes healthy immune function. Research shows that vitamin D also plays a critical role in digestive health, specifically in your gut microbiome.

Vitamin D promotes the absorption of calcium in your gut through the intestinal epithelial barrier. Without vitamin D, your gut would not be able to absorb the calcium which your body uses in a variety of ways such as the formation of healthy bones. Your gut microbiome also helps your body make vitamins, absorb nutrients, renews cells in your gut and even develops brain function.

Vitamin D is available in a variety of ways including natural or fortified food and from the sun or supplements. If you think you are not getting enough vitamin D, talk to your doctor about ordering a blood test.

Find a doctor near you.