Somebody currently has a question up about low VD levels despite supplementation, and everyone seems to think that the solution is to supplement more heavily given the various details of his or her situation. However, consider the following:
My friend who is a biochemistry PhD student recently told me that she saw a talk at a conference about how supplements can harm receptors by overloading them with high doses, which make them less receptive to the vitamin/mineral in question. Some of his data included a study of the effects of vit D supplements, and he reported that elderly patients who supplemented with 5,000 daily IU of vit D had weaker bones - according to post mortem analyses - than controls with no supplementation. He interpreted this to indicate that their receptors were rejecting the vit D in the supplements, an outcome which probably developed over time in response to the frequent high doses. Now, we are talking about a population of elderly patients who are close to death, and I'm afraid I don't have a link to this talk, but the overall idea makes sense, and seems worth looking into - hence my Q to all you Paleohackers.
Does anyone know anything about this? Opinions? Actual knowledge of it?
The researcher is David Agus and a talk of his can be found here: