Published on August 30, 2021

Could taking certain medications alter vitamin D metabolism and status?

There are several factors that can affect vitamin D levels for individuals, besides vitamin D intake and sun exposure, including a person’s age, skin color, genetics, where they live, and certain chronic diseases. Digestive disorders can decrease the absorption of vitamin D, resulting in a lower vitamin D level, as can a lack of specific co-nutrients, such as magnesium. Also, some medications including statins, prednisone and weight-loss drugs, can block vitamin D absorption and/or metabolism, increasing the risk of low vitamin D levels and vitamin D deficiency.

How Can Medications Impact Vitamin D Levels?

There are several ways in which medications may affect the absorption, metabolism, and regulation of vitamin D. For example, the same enzyme (25-hydroxylase CYP3A4) that metabolizes about half of all medications is responsible for transforming supplemental vitamin D3 and D2 to 25(OH)D. Also, since vitamin D is a fat-soluble vitamin, certain medications that block dietary fat absorption or enhance its elimination may also have a negative effect on vitamin D absorption, therefore increasing the risk of deficiency.

More People Taking Multiple (5 or More) Medications at a Time

With an increased number of medications taken by an individual concurrently, the risk of those medications having an effect on their vitamin D level also increases. According to a review by Wakeman, M, there has been a significant increase over the past couple decades of individuals taking five or more medications at any given time. This is especially prevalent among the elderly (those ages 65 years and older). In fact, in the UK alone, the percentage of elderly taking five or more medications increased from 12% to 49%; a 4-fold increase over two decades. This increased use of medication among the elderly is especially concerning, since the risk of vitamin D deficiency increases with age.

One study in particular looked at the relationship between the risk of vitamin D deficiency and the number of medications being taken among 1000 community-dwelling Dutch citizens. 49% of the population was vitamin D deficient, with levels below 20 ng/ml or 50 nmol/L. When looking at levels among those who did not take a vitamin D supplement, the use of multiple medications was found to be a significant factor in negatively affecting vitamin D levels.

What Medications Might Affect Vitamin D?

The table below contains a list of medications and their potential effects on vitamin D, as reviewed by Wakeman.

Click to Enlarge & Print

Importance of Measuring Vitamin D When on Certain Medications

In conclusion, the authors stress the importance of monitoring vitamin D levels and supplementing as necessary “with the objective of achieving adequate levels of vitamin D while also optimizing the efficacy of treatment and limiting drug side-effects and toxicity.”

Are Your Vitamin D Levels OK?

Having and maintaining healthy vitamin D levels and other nutrient levels can help improve your health now and for your future. Choose which to measure, such as your vitamin D, omega-3s, and essential minerals including magnesium and zinc, by creating your custom home test kit today. Take steps to improve the status of each of these measurements to benefit your overall health. You can also track your own intakes, symptoms and results to see what works best for YOU.

Enroll and test your levels today, learn what steps to take to improve your status of vitamin D (see below) and other nutrients and blood markers, and take action! By enrolling in the GrassrootsHealth projects, you are not only contributing valuable information to everyone, you are also gaining knowledge about how you could improve your own health through measuring and tracking your nutrient status, and educating yourself on how to improve it.

Help everyone Move Research into Practice with vitamin D and other nutrients! As a special birthday gift to everyone, in honor of the science, we have created a special scholarship fund for anyone to donate to that will go towards helping others participate. Your donation will allow anyone to get help with funding their participation when they need it.

Text-to-give: Text Daction to 44321 to add to our Scholarship Fund.

What Does it Take YOU to Get Your D to 40 ng/ml (100 nmol/L)?

Did you know your health could be greatly affected by making sure you have a vitamin D level of at least 40 ng/ml (100 nmol/L)? Help us help you.

STEP 1 - Do you know what your vitamin D level is? If not, be sure to test today to find out.

STEP 2 – Determine your target level. Are you at your target level? Experts recommend a level of at least 40-60 ng/ml (100-150 nmol/L).

STEP 3 – Need to boost your level? Use the D*calculator to see how much vitamin D it may take to reach your target. Opt for the Loading Dose for a quicker boost.

STEP 4 – Optimize how your body absorbs and utilizes vitamin D with co-nutrients and these simple steps.

STEP 5 – Re-Test! This is an important step to make sure you have reached your target level, and to ensure you are not taking too much! Re-testing after 3-4 months is recommended.

STEP 6 – Adjust, Repeat…

Give your immune system the nutrients it needs to support a healthy you and protect yourself from unnecessary diseases, especially COVID-19.


The first Randomized Controlled Trial on vitamin D and COVID-19 has shown a 96% lower risk of ICU admission for those receiving vitamin D (as 25(OH)D to quickly boost vitamin D blood levels) along with the standard treatment, compared to those receiving standard treatment alone.

These results support many previous observational studies showing a relationship between vitamin D levels and intake and COVID-19 severity.

Review the Latest Nutrient Research for COVID-19

GrassrootsHealth Nutrient Research Institute has launched the new Immune Boost project with the use of our myData-myAnswers nutrient health system that nearly 15,000 people are already using for their health. Specific markers that influence immune health are suggested for testing as part of this project including:

  • Vitamin D
  • Omega-3 Index
  • Essential elements magnesium, selenium, and zinc
  • hsCRP

Our goal is to demonstrate how one can use the Nutrient Research Model established by Dr. Robert Heaney to show the effect of vitamin D serum levels of at least 40 ng/ml (100 nmol/L) on risk reduction for all ethnicities in the population. Status and intake of other nutrients will also be analyzed for any type of relationship to immune status and symptom severity. Join the project today!

Please let us know if you're interested in helping sponsor this project.

CLICK HERE for updates and new information about the project.

Through GrassrootsHealth Nutrient Research Institute, you can also test your essential elements magnesium, copper, zinc and selenium, toxins such as lead, mercury and cadmium, as well as your omega-3 levels, inflammation levels and thyroid stimulating hormone (TSH) level. Find out your levels today! Log on to the test selection page (click the link below) to get your tests and see for yourself if your levels can be improved.

Make sure you track your results before and after, about every 6 months!

Click Here to Access the Test Page

How can I track my nutrient intake and levels over time?

To help you track your supplement use and nutrient levels, GrassrootsHealth has created the Personal Health Nutrient Decision System called

For each specific supplement, you can track what days you take it, how much, and many other details.  This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels. Check it out today!