Comment by fylham

The author of this paper, Michael Holick, was a professor of mine and is highly controversial due to his industry conflicts of interest that he didn't disclose (https://www.nytimes.com/2018/08/18/business/vitamin-d-michae...) and his seemingly perverse testimony in child-abuse cases (https://www.propublica.org/article/michael-holick-ehlers-dan...). I regard his research with high suspicion.