Drugs which create a vitamin D deficiency

Holick, author of: The Vitamin D Solution - 2010 pg 236 & 237

Antiseizure - need 2X or 3X more to compensate
Prednisone
AIDS drugs
St Johns wort
Orlistat (for obesity) need 3000 to 4000 IU
Questran (lower cholesterol) wait 2-4 hours after taking the medicine before taking vitamin D

Zaidi, author of: Power of Vitamin D - 2010 pg 24

Dilatin
Phenobarbital
Rifampin
Orlistat
Questran
Steroids - severe

Statins and vitamin D

24 million Americans are now taking statins

Cholesterol is not a drug, but reducing it MIGHT reduce vitamin D

2 page summary of drug interactions with vitamin D

University of Maryland

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Also mentioned at hubpages

Antacids — Taking certain antacids for long periods of time may alter the levels, metabolism, and availability of vitamin D.
Calcium channel blockers (such as verapamil ) — These medications, used to treat high blood pressure and heart conditions, may decrease the production of vitamin D by the body.
Cholestyramine — This cholesterol-lowering medication, known as a bile acid sequestrant, interferes with the absorption of vitamin D (as well as other fat-soluble vitamins).
Phenobarbital, phenytoin (brand name Dilantin®), and other anticonvulsant medications — These medications may accelerate the body's use of vitamin D.
(confirmed Office Dietary Supplements Feb 2011)
Mineral oil — Mineral oil also interferes with absorption.
Weight loss products — Orlistat (also known as alli), a medication used for weight loss, and olestra, a substance added to certain food products, are both intended to bind to fat and prevent the absorption of fat and the associated calories.
(confirmed Office Dietary Supplements Feb 2011), but no longer in potato chips)