Just when you think that science can't get any more confusing, out comes another study turning everything on its ear. For instance, we used to uniformly recommend calcium supplements to just about anyone. Then last month, another in a series of studies linking calcium supplementation to heart disease was published. Well, heart disease is one thing, but we've all got to die of something, so all-cause mortality really is the holy grail. So to add to my growing confusion after yesterday's post, I then read a meta-analysis published early online in the Journal of Clinical Endocrinology & Metabolism that concluded that vitamin D plus calcium reduced mortality but vitamin D alone did not.
The authors pored over individual patient data from 8 randomized controlled trials involving 70,528 mostly female participants average 70yo who were followed for 3 years. Those who were randomized to vitamin D plus calcium had a statistically significant 9% lower all-cause mortality compared to those randomized to vitamin D alone. They concluded that we would need to treat 151 people with vitamin D plus calcium for 3 years to prevent one death. For comparison's sake, you'd need to treat 1,667 w/daily aspirin for a year to prevent a first heart attack or stroke. Or you'd need to treat 333 w/known heart disease or stroke w/daily aspirin for a year to prevent one death.
The authors expanded their analysis to trial level data involving 24 randomized controlled studies of 88,097 participants and found a 6% reduction in all-cause mortality in those given vitamin D plus calcium. Those randomized to vitamin D alone had no benefit.
So is vitamin D good or bad for you? What about calcium? If you read this study in isolation, the answer is easy: vitamin D plus calcium is better than vitamin D alone. But when you read this study in context with yesterday's post and other recent vitamin D flip flops, it's not that easy to come to a simple conclusion. Stay tuned for Part 3 tomorrow.
Tweet
No comments:
Post a Comment