Recently, Dr Basmaa Ali of Harvard Medical School and her colleagues in Pakistan used mega doses of vitamin D (called stoss doses) to find out if there was a reliable way of diagnosing vitamin D deficiency that did not involve a blood test. They used a scale of lower leg pain upon pressure over the tibia as a diagnostic marker, instead of a 25(OH)D blood test, which costs too much in Pakistan.
The authors point out that a 25(OH)D blood test in Pakistan costs 25 dollars. However, the average amount of money spent on health care per year in Pakistan is only 22 dollars. So clearly they cannot afford 25(OH)D blood tests and need to develop a cheap and easy way to detect vitamin D deficiency.
The authors measured lower leg bone pain by using an instrument that pushes on the tibia and also measured 25(OH)D and parathyroid hormone (PTH). Then they gave these 75 women a total of 1,800,000 IU of vitamin D3 (a very large stoss dose) given as three intramuscular injections over five days. Mean vitamin D levels rose from 12 to 52 ng/ml in 3 months (P=.01), while PTH dropped from a mean value of 82 to 40 pg/ml (p=.01).
The mean tibial tenderness score of the women was 6.3 at the onset but dropped to a mean value of 4.00 three months after the vitamin D injections (P=.01). The change in tibial tenderness did not show a significant correlation with the vitamin D levels (p=0.157). However, tibial tenderness varied directly with the change in PTH (r= 0.422, p=0.013). So, the authors concluded that tibial pain is a reliable indicator of vitamin D deficiency.
A similar method has been developed to identify vitamin D deficiency by applying force to the sternum. In theory, the bone pain may actually be mild to moderate subclinical osteomalacia, which is more common than you’d think.
The stoss dose of vitamin D used in this case may have shown some subsequent hypercalcemia if calcium levels were measured a week or two after the 1,800,000 IU injection. However, three months after this large dose, the vitamin D levels were in the natural range. And none of the women suffered obvious ill effects. The only thing it did was normalize PTH and help relieve their bone pain. That being said, such a high dose is only meant for use in studies, and not for optimal health, so please avoid such high doses.