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Edited on Fri Dec-04-09 04:02 AM by tiptoe
from: Safety & two MD general recommendations: "How Much Vitamin D Should I Take?"... How Much Vitamin D Should I Take?Again, we don't know. This is a difficult question because it relies on so many personal factors. Everyone's situation is either a lot, or at least a little, different. How much vitamin D you need varies with: - age
- body weight
- percent of body fat
- latitude
- skin coloration
- season of the year
- use of sunblock
- individual variation in sun exposure, and—probably—
- how ill you are
As a general rule, old people need more than young people, big people need more than little people, heavier people need more than skinny people, northern people need more than southern people, dark-skinned people need more than fair-skinned people, winter people need more than summer people, sunblock lovers need more than sunblock haters, sun-phobes need more than sun worshipers, and ill people may need more than well people. Quite a few factors are involved, as you can see. However, don't feel bad, no one understands it. Vitamin D is used by the body—metabolically cleared—both to maintain wellness* and to treat disease. - If you get an infection, how much vitamin D does your body use up fighting the infection?
- If you have cancer, how much vitamin D does your body use up fighting the cancer?
- If you have heart disease, how much vitamin D does your body use up fighting the heart disease?
- If you are a child with autism, how much vitamin D does your brain need to turn on the genes that autism has turned off?
- If you are an athlete, how much vitamin D does your body use to make you stronger and quicker?
Nobody knows the answer to these questions. ... – John Cannell, MD 2008/10/01 Am I Vitamin D Deficient?*(ed: link added — latest recommended optimal serum vitamin D levels, per six experts) Two MD General Dosage Recommendations... Safety ... Cholecalciferol, Not Ergocalciferol, Is SafeAlthough there are documented cases of pharmacological overdoses from ergocalciferol, the only documented case of pharmacological—not industrial—toxicity from cholecalciferol we could find in the literature was intoxication from an over-the-counter supplement called Prolongevity. On closer inspection, it seemed more like an industrial accident, but it was interesting because it gave us some idea of the safety of cholecalciferol. The capsules consumed contained up to 430 times the amount of cholecalciferol contained on the label (2,000 IU). The man had been taking between 156,000–2,604,000 IU of cholecalciferol a day (equivalent to between 390–6,500 of the 400 unit capsules) for two years. He recovered uneventfully after proper diagnosis, treatment with steroids, and sunscreen. It is true that a few people may have problems with high calcium due to undiagnosed vitamin D hypersensitivity syndromes such as primary hyperparathyroidism, granulomatous disease, or occult cancers, but a blood calcium level, PTH, 25(OH)D, and calcitriol level should help clarify the cause of the hypersensitivity. Although D can be toxic in excess, the same can be said for water. Therapeutic IndexAs a physician, I know that psychotic patients should drink about 8 glasses of water a day. However, many would hurt themselves by regularly drinking 40 glasses a day (called compulsive water intoxication). So you could say that water has a therapeutic index of 5 (40/8). Heaney's recent research indicates that healthy humans utilize about 4,000 units of vitamin D a day (from all sources). However, 40,000 units a day, over several years, will hurt them. Therefore, vitamin D has a therapeutic index of 10 (40,000/4,000)—twice as safe as water. We are not saying vitamin D is as safe as water, we are saying vitamin D is safe when used in the doses nature uses. Sun Supplies 10,000 Units Of Vitamin DThe single most important fact anyone needs to know about Vitamin D is how much nature supplies, if we behave naturally, e.g., go into the sun. Humans make at least 10,000 units of vitamin D<3> within 30 minutes of full body exposure to the sun, what is called a minimal erythemal dose. Vitamin D production in the skin occurs within minutes and is already maximized before your skin turns pink. ... – John Cannell, MD 2009/06/20 The Truth About Vitamin D Toxicity- The good news is that in the current literatureNO TOXICITY reported BELOW 500nMol/L == 200 ng/mL*That's not to say there might not be a paper tomorrow that comes out at 190 ng/mL or something like that...but the available literature says that you have to be above 200 ng/mL (500nMol/L), before you have to worry about toxicity.
- Similarly, there's NO TOXICITY below 30,000 IU/day—for long periods of time, not just single doses.
- The paper concluded that the Tolerable Upper Intake Level should be set at 10,000 IU/day. Now, once again, nobody's recommending 10,000, but that's a factor of 3 safety, and — even there — I can't think of many clinical situations which that might be useful, if any.
Any benefit of vitamin D needs to be balanced against the risk of toxicity, which is characterized by hypercalcemia. Daily brief, suberythemal exposure of a substantial area of the skin to ultraviolet light, climate allowing, provides adults with a safe, physiologic amount of vitamin D, equivalent to an oral intake of about 10,000 IU vitamin D(3) per day, with the plasma 25-hydroxyvitamin D (25(OH)D) concentration potentially reaching 220 nmol/L (88 ng/mL). The incremental consumption of 40 IU/d of vitamin D(3) raises plasma 25(OH)D by about 1 nmol/L (0.4 ng/mL). High doses of vitamin D may cause hypercalcemia once the 25(OH)D concentration is well above the top of the physiologic range. The physiological buffer for vitamin D safety is the capacity of plasma vitamin D-binding protein to bind the total of circulating 25(OH)D, vitamin D, and 1,25-dihydroxyvitamin D <1,25(OH)2D>. Hypercalcemia occurs when the free concentration is inappropriately high because vitamin D and its other metabolites have displaced 1,25(OH)2D from vitamin D-binding protein. Evidence from clinical trials shows, with a wide margin of confidence, that a prolonged intake of 10,000 IU/d of vitamin D(3) poses no risk of adverse effects for adults, even if this is added to a rather high physiologic background level of vitamin D. ... Physicians think vitamin D itself causes calcium aborption. That's why we've had to overcome this idea that Vitamin D can be toxic in the types of doses we're typically using: It doesn't cause an increase in calcium absorption; it doesn't cause hypercalcemia; and it doesn't cause hypercalciuria — in the kinds of doses we're talking about. ... Our study highlights that 100 000 IU cholecalciferol is a safe, efficient, and cost-effective means to increase calcidiol concentrations in the elderly. From this study we can safely recommend 100 000 IU cholecalciferol dosed every 2 mo in persons with moderate baseline calcidiol concentrations. However, in those persons with baseline calcidiol concentrations < 20 ng/mL, even this large dose will not adequately raise their calcidiol concentrations.
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Disease Incidence Prevention by Serum 25(OH)D Level --Cancers, Diabetes, MS, Fractures, HeartAttacks Including optimal levels of serum 25(OH)D recommended and targeted by six doctors
Overview: Myths, FAQ, "...Vitamin D: A Real Missing Link..." Prescription=D2 vs D3, Testing, Optimal Ranges
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