These Drugs Interfere with Vitamin D Absorption

In our previous posts on vitamin D we've discussed how to get your serum D level checked, how much D you need to include in your diet - either through supplement, foods or sun - how much sun you need to get to produce a substantial amount of D and many other topics.
One thing we haven't discussed is the medications that could interfere with the absorption of vitamin D.

The current recommended daily allowance for D appears to be low according to the many vitamin D researchers that are experts in this field of study.
We know that we are in the midst of a vitamin D deficiency epidemic, and that we need to take pro-active steps to rectify this crisis.

Since we are all trying our best to get the right amount of D I think it's important to know that some medications can inhibit the absorption of D and we wanted to give you a list of those medications.

Below is a list of medications that interfere with the absorption of D which could cause further deficiencies than what we are already dealing with.
Since the correct amount of D is so essential for the treatment of bone loss and many other health concerns like cancer, heart disease, arthritis, diabetes, and autoimmune diseases;
it seems to me to be very important to know if we are taking something that would further complicate our daily routine of getting the proper amount of D.

Drugs That Affect the Absorption of Vitamin D

Aluminum or Magnesium containing antacids

Thiazide and similar diuretics

Anticonvulsants (Carbamazepine

St. John's wort

Antiretrovirals (AIDS therapies)


Antirejection medications (after organ transplant)

Mineral Oil (may influence hypocalcemia)

Barbiturates (Phenobarbital

Stimulant Laxatives

® and Colestipol
® (anticholesterol agents)


Corticosteroids and Glucocorticoids

Gastric bypass

Hydroxychloroquine (Plaquenil


® (bactericidal antibiotic)


Note that these items may affect the absorption of vitamin D, but your Doctor can adjust your vitamin D dose to correct this malabsorption.
Conversely, vitamin D doesn't affect the actions of these drugs on the body, so vitamin D has no deleterious affect on the above medications and their benefits.

If you are taking one of these medications with vitamin D, check with your Doctor to see if there needs to be an adjustment in the amount of D you take with these drugs.

Important Note:
Patients with hypercalcemia should avoid prescribed high doses of vitamin D.

I hope this information helps you to gain the full amount of vitamin D that you take without causing any vitamin D malabsorption or adjustment.

Drug List Sources:

Bringhurst et al. 2005; Calcitriol 2007; Ergocalciferol 2007; Holick 2007;

Hollis et al. 2005; Marcus 1995; Mascarenhas and Mobarhan 2004; ODS

2005; Turner et al. 2008.

Pam Flores
Meet Our Writer
Pam Flores

Pam wrote for HealthCentral as a patient expert for Osteoporosis.