Dr Gareth

Medically reviewed by Gareth James, GP, GMC, DRCOG, DFFP, MRCGP on December 2, 2023. To give you technically accurate, evidence-based information, content published on the Check My Body Health blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Vitamin D, often referred to as the “sunshine vitamin,” plays a crucial role in various functions within the body. From bone health to immune system support, its benefits are numerous. There have been claims and concerns that vitamin D supplements cause constipation. In this comprehensive guide, we look into the relationship between vitamin D and constipation. We explore the reasons behind this perception. We explain the importance of vitamin D. Examine potential side effects of excessive vitamin D intake. Investigate other vitamins that might contribute to constipation. We discuss methods to test vitamin D levels, and identify foods that can help maintain adequate vitamin D levels.

What is Vitamin D?

Vitamin D is a fat-soluble vitamin that plays a vital role in several key bodily functions. There are two primary forms of vitamin D: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D2 is found in some plants and fungi. While vitamin D3 is primarily synthesised in the skin in response to exposure to ultraviolet B (UVB) rays from the sun. Both forms can be obtained from dietary sources and supplements

Why is Vitamin D important?

Vitamin D is like the body’s helper that does some really important jobs.

First, it makes sure our bones and teeth stay strong. It works with calcium and phosphorus, which are like the building blocks for our bones.

But that’s not all – Vitamin D also helps our immune system, which is like our body’s defense team. It makes sure we can fight off germs and stay healthy.

And here’s the cool part: our body can make Vitamin D when our skin gets sunlight. So, spending some time outdoors in the sun is like giving our body a boost of this important vitamin.

What Are the Side Effects of Too Much Vitamin D?

Having too much Vitamin D isn’t good for our bodies. It can lead to some problems.

One issue is too much calcium in our blood. It’s like having too many workers for our bones, and things can get messed up. This might make us feel really tired, give us stomach problems, or even hurt our kidneys.

Our body sometimes tells us it’s got enough Vitamin D by making us feel sick. Like having a stomachache or headaches. It’s like a signal to stop taking in more Vitamin D.

So, while Vitamin D is good for us, we need to be careful not to get too much. It’s all about finding the right balance.

Why Might Vitamin D Cause Constipation?

While there’s limited proof directly saying vitamin D can cause constipation. Some ideas try to explain why some folks might feel this way.

One idea is about calcium. Vitamin D helps absorb calcium in our guts. Too much calcium can lead to constipation. So, if vitamin D pills make us absorb a ton of calcium, it might cause constipation for some.

Another thought is about water. Some people might not drink enough water when taking vitamin D pills. This can make them dehydrated. Dehydration often causes constipation.

Also, vitamin D helps our muscles work, and if we don’t have enough, our muscles might get weak. Not moving around a lot can also lead to constipation.

And here’s the thing: everyone’s different. Our bodies react in their own ways. Depending on things like our genes, how healthy we are, and the tiny living things in our guts. So, when it comes to vitamin D and constipation, it’s kind of like a puzzle. We need to pay attention to all these pieces to figure it out.

Do Vitamin D Supplements Cause Constipation?

Similar to the above, some people think vitamin D supplements might make you constipated. There’s not a lot of strong proof for that. Constipation is affected by things like what we eat, how much water we drink, how active we are, and how healthy we are.

Are there other vitamins that might contribute to constipation

Like vitamin D, some other vitamins could play a role in constipation. Though it’s not always clear-cut.

Certain types of iron supplements, often found in multivitamins, might cause constipation in some people. Iron is important for our blood, but too much of it from supplements can slow down our digestive system.

Calcium supplements, similar to the calcium interaction with vitamin D, can sometimes lead to constipation when taken in excess. It’s like our body’s way of saying, “Hey, let’s not have too much of a good thing.”

Remember, everyone’s body is different. So, what affects one person might not affect another in the same way. If you’re ever concerned about vitamins and how they might be influencing your digestion, it’s a good idea to chat with a healthcare professional.

How to test your Vitamin D levels?

If you think you might not have enough vitamin D or are thinking about taking vitamin D pills. Getting a test is a good idea. The most common test checks your vitamin D levels in your blood. They look at something called 25-hydroxyvitamin D [25(OH)D], and it shows how much vitamin D you have overall.

Doctors say that having less than 30 nanograms per milliliter (ng/mL) means you don’t have enough vitamin D. If it’s between 30-50 ng/mL, it’s not quite enough. But if it’s above 50 ng/mL, that’s good. Still, the right amount can depend on your health, so it’s smart to talk to a doctor for personalised advice.

What Foods Help You Get Enough Vitamin D?

Ensuring an adequate intake of vitamin D can involve incorporating specific foods into your diet. Here are some good options:

  • Fatty Fish: Rich sources of vitamin D include fish such as salmon, mackerel, and trout, providing a substantial dietary contribution.
  • Egg Yolks: The yolk of eggs is a natural source of vitamin D, enhancing dietary intake.
  • Mushrooms: Certain varieties of mushrooms can synthesise vitamin D when exposed to sunlight, contributing to the dietary supply of this essential nutrient.
  • Fortified Foods: Some food products, such as select types of milk, orange juice, and cereals, undergo fortification, a process where extra vitamin D is added to enhance nutritional content.

By incorporating these foods into your diet, you can support the body’s vitamin D requirements, promoting overall health and well-being.

The USA's Highest Rated Food Intolerance Test