In acute hypervitaminosis D, there can be organ calcification that has to be treated. These cases are rarely reported - one case occurred when the patient ingested crystalline vitamin D - dosing themselves in the range of 1-2 million IU D3 per day for weeks, and although there was not an extensive follow-up to determine the long-term effect on the patient, the acute calcification was reversed with treatment.
Vitamin D is involved with calcium in the body in many different ways, specifically I was talking about a measure of the absorption of calcium into the body from food as promoted by vitamin D.
Organ calcification is extremely serious and a very understandable reason why doctors have been hesitant to recommend higher doses of vitamin D, however most medical thinking about vitamin D until recently has focused on the prevention of Rickets, which requires only a small amount of constant supplementation (500 IU D3) to avoid serious effects. In context, 10,000 IU seems like an enormous dose. However if you look at the blood serum levels of people who receive consistent UV exposure, they have much higher levels than someone who is being supplemented with 500 IU D3 and no UV. So much of this debate is around trying to find out what the "optimal" vitamin D level is rather than what level is "sufficient" to prevent Rickets.
Vitamin D is involved with calcium in the body in many different ways, specifically I was talking about a measure of the absorption of calcium into the body from food as promoted by vitamin D.
Organ calcification is extremely serious and a very understandable reason why doctors have been hesitant to recommend higher doses of vitamin D, however most medical thinking about vitamin D until recently has focused on the prevention of Rickets, which requires only a small amount of constant supplementation (500 IU D3) to avoid serious effects. In context, 10,000 IU seems like an enormous dose. However if you look at the blood serum levels of people who receive consistent UV exposure, they have much higher levels than someone who is being supplemented with 500 IU D3 and no UV. So much of this debate is around trying to find out what the "optimal" vitamin D level is rather than what level is "sufficient" to prevent Rickets.