The Dangers of Too Much Vitamin D

  • By Rachel Perlmutter
  • May 26
Girl in the sun
  • 42% of the U.S. population is Vitamin D deficient and this can have a number of negative affects on your health, most significantly bone density issues. That’s why so many people take Vitamin D supplements. But are people taking too many Vitamin D supplements and is it hurting them?
  • During the COVID-19 pandemic, Vitamin D supplements saw a major surge, according to the Council for Responsible Nutrition (CRN)’s 2021 Consumer Survey on Dietary Supplements. In a survey of 3,089 adults in the U.S. it was found that four in five consumers take supplements and Vitamin D usage in particular rose from 42% in 2020 to 52% in 2021. But, did they all need this much Vitamin D?
  • In this article, we want to help you see if you are taking too much Vitamin D. Do you know what the risks of taking too much Vitamin D are? We will break down what Vitamin D is, what body processes it is involved in, why it’s beneficial but also why too much of it can be detrimental to your health.

If you walk right outside your door on a sunny day, you can get yourself a dose of Vitamin D (in most cases) and yet so many Americans are lacking this essential nutrient that is extremely important for calcium absorption and keeping your skeleton strong and healthy. In fact, about 42% of the U.S. population is Vitamin D deficient. Certain groups are worse off than others including premenopausal women, people over 65, nutrition deficient people, and people on long term medications for heartburn and acid reflux. People with higher amounts of melanin in their skin, including Latinos and African Americans, are also at risk as the pigment makes it more difficult for the body to convert Vitamin D from sunlight.

Why we need Vitamin D

Low levels of Vitamin D, also known as the sunshine vitamin, can lead to major health problems. Increased rates of bone loss or even osteomalacia in adults and rickets in children are the major ones, but there are other parts of the body that can be impacted. A recent study found an association between low Vitamin D levels and reduced brain volume. The researchers found that Lower vitamin D was also linked to an increased risk of stroke and dementia.

But wait, Vitamin D does more! It also helps reduce inflammation and promotes cell growth, glucose metabolism and neuromuscular function. And it is critical to a healthy immune system. In other words, Vitamin D is essential for growing and staying healthy.

How we get Vitamin D naturally

Most people are able to get enough Vitamin D, a fat-soluble vitamin, through the sun and certain foods. It is produced in the body when UV rays from the sun are absorbed by the skin and Vitamin D synthesis occurs which is then passed on to your liver and kidneys where it then becomes active Vitamin D. In the liver it is converted into calcidiol and in the kidney it becomes calcitriol.

You are also able to get the two kinds of Vitamin D, vitamin D2 and vitamin D3, from foods including fatty fishes like salmon and tuna as well as mushrooms, egg yolks and beef liver. Vitamin D occurs naturally in these foods but you can also opt for Vitamin D fortified foods such as orange juice, cereal, milk and some types of yogurt. Incorporating these foods into your diet is important, but sun-derived Vitamin D may circulate for twice as long as Vitamin D from food or supplements.

Most of the population should get 600-800 IU (International Units) of daily Vitamin D in order to have sufficient levels, according to a recommendation from the U.S. National Academy of Medicine. But there are some segments of the population that are Vitamin D deficient. People with high body mass indexes are at risk as well as those who are over the age of 65. This can be due to their diets and lack of sun exposure. People with dark skin are also at higher risk of Vitamin D defieciency. Pigment in darker skin blocks sunlight absorption, which as we learned above is essential for Vitamin D conversion.

People who have less access to sunlight are also at risk. Whether they are unable to get outside because they are sick or they simply don’t make an effort, this can be detrimental as this is the most efficient way to receive Vitamin D.

The rise of Vitamin D supplements

Vitamin D has so many benefits, so you can imagine people want more of it (and no, tanning beds are not the answer.) As we mentioned above, supplements really took off during the pandemic and Vitamin D was a huge part of that. In a survey of 3,089  adults in the U.S., it was found that four in five consumers take supplements and Vitamin D usage in particular rose from 42% in 2020 to 52% in 2021.

But like many things, sometimes too much can be detrimental. Researchers have warned about the dangers of over supplementing with Vitamin D in particular. The French Agency for Food, Environmental and Occupational Health & Safety (ANSES) stated that excessive intake of Vitamin D can lead to hypercalcemia (elevated blood calcium levels.) This can lead to many issues including plaques forming on the walls of arteries which can cause nausea, vomiting, frequent urination and overall weakness. In more extreme cases, it can also lead to bone pain and kidney issues.

Signs that you have taken too much Vitamin D

Signs that you may have too much Vitamin D include elevated blood and calcium levels as mentioned above and gastrointestinal symptoms which are caused by the excess calcium. Nausea, poor appetite, diarrhea and constipation can also occur.

According to The Mayo Clinic, the recommended daily amount of Vitamin D is 400 international units (IU) for children up to age 12 months, 600 IU for people ages 1 to 70 years, and 800 IU for people over 70 years of age. In almost every case, overdosing is almost always caused by taking supplements, as opposed to sunlight exposure or eating Vitamin D–rich foods.

If your blood levels have been tested by your doctor and you are found to be Vitamin D deficient, he or she will most likely prescribe you a Vitamin D supplement. The most common forms of supplements are vitamin D2 and vitamin D3. The recommended dose of the supplement will depend on how bad the deficiency is. To give you context, prescription Vitamin D supplements contain 50,000 IU and over-the-counter Vitamin D supplements have up to 10,000 IU.


Puori Vitamin D3

After a few weeks of prescribed supplements, you may be able to switch to a non-prescription supplement to keep your levels up. One version of Vitamin D3 we carry is Vitamin D3 + K2 Liquid Drops. Liquid supplements can be a great source as they don’t need to be broken down in order to digest, which is useful for people with low stomach acid levels. Liquid supplements also have better bioavailability and are easy to titrate based on personal needs.

We recommend consulting with your doctor before taking any type of Vitamin D supplement.

The information contained in this article is for educational and informational purposes only. It is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.