Measuring vitamin D levels: surrogates are insufficient.
Heald AH, Anderson SG, Scargill JJ, Short AD, Holland D, Livingston M, Fryer AA, Donn RP.
Heald AH, et al. Among authors: livingston m.
Int J Clin Pract. 2015 Jan;69(1):131-5. doi: 10.1111/ijcp.12505. Epub 2014 Oct 31.
Int J Clin Pract. 2015.
PMID: 25359317