more on vitamin D dosage

Here are a number of links and the latest studies on vitamin D dosage.

Since so many have mentioned increased Vitamin D dosages lately..I think it would be good to look at the issue.

Here is a must read interview with Dr Vieth on Vitamin D dosage


The following link gives some balanced guidelines on Vitamin d dosage by a medical doctor. The entire site, developed by scientists, professors and MD.s is entirely nonprofit and its goal is to promote good science in regards to vitamin D..it's a good read... http://www.vitamindcouncil.com/treatment.shtml

A call this march by scientists from all over the world (checkout the authors) to adjust dosages to meet the needs http://www.ajcn.org/cgi/content/full/85/3/649#FN2 upper limit "UL limit should be 10,000iu/day"

another technical study by Dr Hollis, prof, of biochemistry http://jn.nutrition.org/cgi/content/full/135/2/317
which concluded..Given the results of these recent scientific studies that evaluated high-dose vitamin D supplementation, it appears that the current DRI for adults are woefully inadequate, misleading, and potentially harmful, placing individuals at undue risk for a number of chronic diseases. The current adult dietary recommendations of 200–600 IU/d are extraordinarily low compared with endogenous production during sun exposure. Reexamination of the requirements for vitamin D is clearly merited and may likely reveal the need for vitamin D intakes exceeding 2000 IU/d for adults.

Here is technical paper written within the last year by four of the top scientists in the field including Reinhold Vieth

http://www.ajcn.org/cgi/content/full/85/1/6

and Vieths 1999 landmark study..http://www.ajcn.org/cgi/content/full/69/5/842


Except in those with conditions causing hypersensitivity, there is no evidence of adverse effects of 10,000 IU/d of Vitamin D. Published cases of vitamin D toxicity with hypercalcemia, for which the 25(OH)D concentration and vitamin D dose are known, all involve intake of 40,000 IU/d. and above.

The desirable objective of mean 25(OH)D concentrations >100 nmol/L, the total vitamin D supply from dietary and environmental sources must be 100 µg (4000 IU)/d.

Vieth goes on to explain in his paper how government guidelines were based on previous faulty testing and anecdotal reports.

Who shouldn't take vitamin D...What are the contraindications for Vitamin D?
The main contraindication is the existence of primary hyperparathyroidism , also individuals with sarcoidosis, tuberculosis, or lymphoma and some cancers may become hypercalcemic when given increased Vitamin D doses. Those on calcium channel blockers and thiazide diuretics should not take vitamin D without a doctors guidance..Some rare individuals are sensitive to Vitamin D at higher doses.

What are the signs of Vitamin D toxicity?
The main signs are sudden hypercalcemia (excessive levels of calcium in the blood) and/or hypercalcinuria (excessive levels of calcium in the urine). Toxicity symptoms are headache, nausea, dizziness, vomiting, loss of appetite and dry mouth. Most of these scientists say it can occur at approx, 40,000iu/day and above. Less if involved with the medical conditions listed above.

two cardiologists blogs dealing with vitamin d dosage

http://www.lewrockwell.com/miller/miller25.html
http://heartscanblog.blogspot.com/search/label/Vitamin%20D%20toxicity%3F

well, something to look at and consider....hope this helps..bj