24-08-2014, 06:40 PM
Blood levels of 35-40 ng/ml appear to be best according to this analysis. However, 30-35 ng/ml appears to be best in this one. Earlier research found that 32 ng/ml was the minimum necessary to avoid vitamin D deficiency, so it doesn't make sense to me that the minimum necessary is also the optimum and I thus choose to believe in the 35-40 ng/ml target. It takes me 5000 IU/day to get there and I monitor it with Labcorp tests purchased through www.lef.org.
Labcorp's reference range (30-100 ng/ml) is absurd and irresponsible. Unlike their other tests where they derived the ranges from actual data, the 100 ng/ml upper limit was pulled out of thin air. In the past they would cite this paper as justification for the range, and the paper says "I have arbitrarily set the toxic level at 250 nmol (100 μg/L)".
Labcorp's reference range (30-100 ng/ml) is absurd and irresponsible. Unlike their other tests where they derived the ranges from actual data, the 100 ng/ml upper limit was pulled out of thin air. In the past they would cite this paper as justification for the range, and the paper says "I have arbitrarily set the toxic level at 250 nmol (100 μg/L)".