What you need to know about Vitamin D
There are a number of varying dosage protocols for taking Vitamin D ranging from 1000IU daily to 25,000IU once to twice a week. Our recommendation based on the work of Drs Cambell and Cannell is to use approximately 5000IU daily in an oil capsule if levels are found to be low. This provides consistent therapeutic doses without causing fluctuations in serum levels and no side effects. This dose would require monitoring by your doctor.
This is a far greater dose than the currently accepted recommended dose established over 30 years ago being 400 to 800IU daily.
More Vitamin D May Be Better?
Recent science is showing that doses above these may provide better health. For example, professor Robert Heaney has reported in April 2006 in the Journal of Nutrition his study showing an additional 2600 IU/day of oral vitamin D3 should be given to older women.
Vieth reported in the American Journal of Clinical Nutrition a recommendation of 4000 IU per day for adults. He also showed that levels of 10,000 IU per day were normal from body exposure to the sun and the only published vitamin D toxicity was at levels exceeding 40,000 IU/day.
It seems more studies are warranted on proper vitamin D doses. Given that vitamin D3 is safe at very high levels and may provide extraordinary benefits with no known risk, we recommend individuals get reasonable sun exposure, eat foods rich in vitamin D, and supplement with 5000IU Vitamin D3 in an oil based capsule. Follow up blood tests will then determine if any dosage adjustments are required.
Vitamin D Toxicity
It is very rare to have a vitamin D overdose. Vitamin D toxicity induces abnormally high serum calcium levels (hypercalcemia), which could result in bone loss, kidney stones, and calcification of organs like the heart and kidneys if untreated over a long period of time.
When the Food and Nutrition Board of the Institute of Medicine established the tolerable upper intake level (UL) for vitamin D, published studies that adequately documented the lowest intake levels of vitamin D that induced hypercalcemia were very limited. Because the consequences of hypercalcemia are severe, the Food and Nutrition Board established a very conservative UL of 2,000 IU/day (50 mcg/day) for children and adults.
Research published since 1997 suggests that this level for adults is overly conservative and that vitamin D toxicity is very unlikely in healthy people at intake levels lower than 10,000 IU/day.
Certain medical conditions can increase the risk of hypercalcemia in response to vitamin D, including primary hyperparathyroidism, sarcoidosis, tuberculosis, and lymphoma. People with these conditions may develop hypercalcemia in response to any increase in vitamin D nutrition and should consult a qualified health care provider regarding any increase in vitamin D intake.
Vitamin D Drug Interactions
The following medications increase the metabolism of vitamin D and may decrease serum D levels:
Phenytoin (Dilantin), fosphenytoin (Cerebyx), phenobarbital (Luminal), carbamazepine (Tegretol), and rifampin (Rimactane).
The following medications should not be taken at the same time as vitamin D because they can decrease the intestinal absorption of vitamin D: Cholestyramine (Questran), colestipol (Colestid), orlistat (Xenical), mineral oil, and the fat substitute Olestra. The oral anti-fungal medication, ketoconazole, inhibits the 25(OH)D3-1-hydroxylase enzyme and has been found to reduce serum levels of 1,25(OH)D in healthy men . The induction of hypercalcemia by toxic levels of vitamin D may precipitate cardiac arrhythmia in patients on digitalis (Digoxin).
1000IU vitamin D oil capsules or alternatively Vitamin D sublingual drops are available here. Alteratvely refer the ordering information page to view the various ordering methods available. Higher doses of 5000IU to 25000IU are available with a valid doctors prescription.