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Information on the latest vitamin D news and research.


Prescription vitamin D2: Why not?

Doctors in the USA often prescribe Drisdol (vitamin D2) for vitamin D deficiency, giving 50,000 IU every week or two for 8-12 weeks. Then, a few give it every month.

Too many forget about their patient’s vitamin D deficiency, thinking the Drisdol has cured it forever. There are two problems with this approach:


About John Cannell, MD


3 Responses to Prescription vitamin D2: Why not?

  1. Rather than suggesting that each person take 5,000iu of D3 per day, perhaps it might serve more people to adopt an approach based on weight – say, “5,000iu of D3 daily for each 100 pounds of weight”.

  2. Brant Cebulla says:

    Ron, obviously it’s a most accurate approach to recommend based on weight, absorption, blood levels, sun exposure habits etc…

    Counter to that, however, is that research shows time and time again, that people/patients often follow directions that are nice and simple and have fewest amount of steps.

    What we need is a controlled trial that compares approaches, and see what actually works best, so we can be evidence-based in how we recommend vitamin D. In such trial, you would communicate a simple “take 5,000 IU/day” in one group, and then communicate the “evaluate your habits/body, and take X amount/day based on YZ” to the other group. Then you can measure vitamin D levels before and after, and actually see what approach is “better”.

    For the time being, my guess is that a simple, “take 5,000 IU” results in more people taking vitamin D than a more personalized message. But who knows?

  3. Veterinarians around thw world ceased giving vitamin D2 to mammals about 10 years ago. There have been >30 reports showing problems with giving vitamin D2 to humans during the past decade, yet the practice continues. Several studies found that the vitamin D blood levels actually DECREASED when taking vitamin D2.

    Be sure to have D3, not D2.

    See all of the reports and some graphs at http://is.gd/vitd3d2

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