The National Academy of Medicine sets the tolerable upper intake level for vitamin D at 4,000 IU a day for adults. Mega Restore contains 5,000 IU. If you are the kind of person who reads labels, and I hope you are, that deserves a straight explanation rather than a shrug.
What the upper limit is, and isn't
The tolerable upper intake level is the highest daily intake judged unlikely to cause harm in nearly everyone in the general population, set with a safety margin. It is not the dose at which harm begins. The toxicity literature for vitamin D involves intakes far above 5,000 IU sustained for long periods, and the marker that matters, 25-hydroxyvitamin D in the blood, rises slowly and predictably with dose and body weight.
Why 5,000
In practice, the patients I see are mostly indoors, mostly over forty, and mostly starting below the range most clinicians consider adequate. In the dose-response work, 5,000 IU a day moves a typical adult into that range over two to three months; 1,000 or 2,000 often does not, particularly in heavier adults. It is a deliberate, higher-end dose chosen for the people this formula is built for, taken once a day with food.
What you should do
Three things. First, do not stack it: if you take a separate vitamin D product or a multivitamin with 1,000 to 2,000 IU in it, drop one of them. Second, if you have kidney disease, hyperparathyroidism, sarcoidosis, or a history of kidney stones, talk to your physician before starting; these are the situations where vitamin D needs supervision. Third, with long-term use, have your 25-hydroxyvitamin D and calcium checked periodically. That is not a warning label reflex; it is what I do for my own patients and for myself.
A dose that deserves a blood test is not the same as a dangerous dose. But you should know the difference before you buy, and now you do.
Mega Restore is 200 mg ubiquinol, 5,000 IU vitamin D3 and 300 mcg vitamin K2 as MK-7 in one daily capsule. $89.99 for a 90-day supply, free U.S. shipping. See the full label and buy.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
