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The difference between two "normals"
March 16, 2012 -- John Cannell, MD
In a paper the press ignored, well-respected researchers from three different hospitals on the east coast recently reported on high blood calcium levels in three infants and toddlers with rickets who were given vitamin D. The reasons for the high blood calcium, all of which were trivial, were not clear from the paper at first, at least to me.
Vanstone MB, Oberfield SE, Shader L, Ardeshirpour L, Carpenter TO. Hypercalcemia in Children Receiving Pharmacologic Doses of Vitamin D. Pediatrics. 2012 Mar 12.
Before we talk about this recent paper, it is important to remember that (in a paper you are free to download and read in its entirety) the entire country of East Germany had a lot of experience with “pharmacological” (very high) doses of vitamin D in children. Unbelievably, for several decades, every child in East Germany went to the doctor every 3 months where the child received 600,000 IU of vitamin D. All the kids in the entire country got it every three months until the child was 18 months old. That means in the first year and a half of life, every child in the German Democratic Republic (East Germany) had a total dose of 3.6 million units of vitamin D.
Markestad T, Hesse V, Siebenhuner M, Jahreis G, Aksnes L, Plenert W, Aarskog D. Intermittent high-dose vitamin D prophylaxis during infancy: effect on vitamin D metabolites, calcium, and phosphorus. Am J Clin Nutr. 1987 Oct;46(4):652-8
That is way too much as the paper above documents but the amazing thing is that only about 1/3 of the children got high blood calcium and none got clinically toxic. In fact, the authors reported, “All the infants appeared healthy . . .” However, they were not all healthy; some had calcium levels as high as 13 mg/dl, too high but far from fatal. The key, and this is critical, is that the range of calcium considered normal in East Germany was 9.4 to 11.2 mg/dl and these were ranges borrowed from Norway. In the USA, “normal” ranges are 9 to 10.5 mg/dl.
How do we get these calcium ranges? We take several thousand vitamin D deficient children, measure their calcium and use a Gaussian distribution to calculate “normal.” How do I know the kids are vitamin D deficient? Because virtually all the kids in the USA are vitamin D deficient, thanks to video games, the sunscare, and sunblock. For the first time in human history, we are raising a generation of indoor children. Because calcium and vitamin D are connected, such children will have slightly lower calcium levels than would several thousand truly “normal” kids. Therefore, we use the abnormal to calculate the normal.
Next comes my second reading of the recent “toxicity” paper. All three children had rickets but their “hypercalcemia” was all below 11.2 mg/dl. That’s right, none of the children had high blood calcium. They had a calcium level that reflected the fact that someone detected their rickets (rather rare) and gave them the correct amount of vitamin D (total doses of around 150,000 IU), hardly the “pharmacological” doses the authors reported. If they want pharmacological doses, they should take a time train back to East Germany. Pity our children, now, because of these three case reports, children desperately in need of vitamin D will not get it, not because of a conspiracy, but due to the failure to know the difference between normal and normal.