We have “known” for years that 25-hydroxy Vitamin D levels over 50ng/ml are “too high” (hypervitaminosis D) and often cause high Calcium levels (hypercalcemia). The Mayo Clinic designed a 10 year study to confirm that causal relationship. It was presented at ASBMR.
NOF and others have called for higher Vitamin D supplementation and higher blood levels. Mayo researchers expected to find many more cases of hypercalcemia related to many more cases of hypervitaminosis D. The numbers of Vitamin D levels above 50ng/ml have doubled during the 10 years. Levels above 80 and 100ng/ml have not increased. The numbers of high calcium levels have not increased. Those patients with the highest Vitamin D levels were not the patients with the highest Calcium levels.
The question whether calcium supplements are good or bad for you, and how much you should take, is very controversial. That is because it is the wrong question. The answer is “it depends”. We spent an hour at ASBMR going over many studies and analyses.
Total calcium intake is what matters. That means that how much calcium supplement you need today depends on how much calcium is in your diet. Unless you eat the same thing every day (boring!), your need for calcium supplement at each meal will vary. And it is more tricky than that.
The American Society for Bone & Mineral Research 35th Annual Meeting has just concluded. Of the roughly 2000 attendees, nearly half were form other countries. Most are PhD researchers dealing in basic science issues and then moving toward answers to human maladies. Two totally new types of osteoporosis medications are in phase 3 human trials. They look promising.
Those of us who treat human patients use meetings to trade information. My poster about using Vertebral Fracture Assessment to improve the accuracy of DXA was well received. Many academic osteoporosis centers routinely use VFA, but have not yet analyzed and reported their results. I learned a lot from other attendees, much of which will help me help my patients.
If you screen by DXA alone you fail to identify most of the individuals who will fracture. Over 80% of fracture patients over age 50 have “osteopenia” or “normal” as their Bone Mineral Density (BMD) test result on DXA. Wow! DXA is a terrible stand-alone test.
Previous fractures are a much more reliable screen. Any previous fracture predicts future fractures. The best predictors of fracture risk are Vertebral (spine) fractures, but there is a problem. Most vertebral “crumble” or even “crunch” fractures are not identified as fractures until you look for them. You must do Vertebral Fracture Assessment (VFA) to identify those persons who are at increased risk of fracture because they already have fractured.