Vitamin D: Not All Supplements Created Equal

Not all supplements are equal when it comes to raising your vitamin D levels. A new study shows vitamin D3 supplements may be more effective than vitamin D2 for mitigating deficiency.

Vitamin D deficiency has been linked to an increased risk of musculoskeletal conditions like back pain as well as autoimmune diseases, hypertension, common cancers, and infectious diseases. Given the high prevalence of vitamin D deficiency, understanding which supplements are most effective could significantly affect patient outcomes.

Scientists have long debated whether vitamin D3 and D2 supplements offer patients the same biological benefits. Some research has suggested that D2 -- often found in plants and mushrooms -- is less biologically active than D3, which is found in animals and humans.

To contribute to the debate, researchers from the University of Bergen in Norway compared the effectiveness of both supplements for raising vitamin D levels in a group of healthy, young volunteers. The study was conducted at a high latitude during the winter, when participants were exposed to virtually no UVB radiation.

After eight weeks, blood tests showed both treatment groups had elevated levels of serum 25-hydroxy vitamin D compared to a placebo group, whose vitamin D levels actually fell. However participants taking vitamin D3 had the greatest improvements.

The researchers said their results "question the usefulness of vitamin D2 supplements," and suggested that instead, vitamin D3 "should be used for supplementation and fortification purposes."

Whether or not you should begin supplementing with vitamin D depends on your medical history, age, diet, level of sun exposure, and presence of a deficiency. Chiropractors often include nutritional counseling in their treatment approach, and can discuss with you whether supplementation would be beneficial for your needs.

Recent research has also suggested that taking probiotics can increase your vitamin D levels.


Lehmann U, et al. Bioavailability of vitamin D2 and D3 in healthy volunteers, a randomized placebo-controlled trial. Journal Clinical Endocrinology and Metabolism 2013; DOI: 10.1210/jc.2012-4287.

Secondary source:

Fiore K. Vitamin D3 may beat D3 as supplement. Medpage Today. September 4, 2013.