Friday, May 28, 2010

Experts Defend Cod Liver Oil, Citing My Work on the Fat-Soluble Vitamins for WAPF!

by Chris Masterjohn

This January, Dr. Linda Linday, a pediatrician who researches cod liver oil, Michael F. Holick, MD PhD, and several other researchers defended cod liver oil against criticism made a year earlier by Dr. Cannell of the Vitamin D Council and 16 other researchers.

They cite the WAPF December 2008 "Cod Liver Oil Update" as an example of the importance of the vitamin A-to-D ratio emerging in the online supplement and nutrition newsletter communities. This update was based largely on the work I have done for WAPF on the fat-soluble vtamins. They suggest the optimal ratio is between four and eight, in IUs.

You can read about it on my blog over at the Weston A. Price Foundation

Drs. Linday and Hollick and Colleagues Defend Cod Liver Oil, Citing the Weston A. Price Foundation!

Read more about the author, Chris Masterjohn, here.


  1. I was wondering if you had seen this paper:
    finding that a once yearly dose of Vit D (500,000U) in elderly women resulted in increased falls and fractures. The serum level initially increased to 120ng/ml then dropped to 90 for the rest of the year. I wonder if the problem stems from the imbalance in vitamins due to the relative deficiency of vitamin K and A to match the increased D (not measured as far as I can tell from the abstract).


  2. Hi Cynthia,

    Those values are nmol/L, not ng/mL. You have to divide them by 2.5 in order to get ng/mL.

    I will have to read this paper in detail before giving final feedback, but I would say that is a possibility, and another is that it resulted from using a single high dose rather than daily small doses, which would be much more natural. Perhaps the excess vitamin D in the system could interfere with the bioavailability of the active forms, for example. One thing that is clear is that an annual massive dose is a pretty bad idea!


  3. Can you clarify the ratio concept a little bit, please? I've seen this described somewhat differently in a number of different places. From what was written HERE, it sounds like I should try to get 4-8 times as much Vitamin A as Vitamin D. That is, if I take a 5000-IU Vitamin D capsule, daily, then I need to take in at least 20,000 IU of Vitamin A every day. Is that correct? Thanks!

  4. They are very careful about their standards and their product is basically as pure as you can get, never heated, never radiated. I’m sorry, again, that you had a poor experience with customer service, but their product isn’t inferior, as you implied.


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