A complex web of interactions between industry, advocacy organisations, and academia may be fuelling enthusiasm for calcium and vitamin D supplements to prevent and treat osteoporosis, despite evidence of lack of benefit, warn doctors in The BMJ this week.
Calcium and vitamin D are highly profitable treatments that are widely recommended for osteoporosis, despite increasing evidence contradicting the practice, write Andrew Grey and Mark Bolland from the University of Auckland.
Several therapies previously recommended for osteoporosis, such as oestrogen and fluoride, have been discarded because of evidence of lack of benefit or important harm. So why are calcium and vitamin D supplements still recommended, they ask?
One possible explanation, they say, is vested interests of industry, advocacy organisations, and academia.
They searched the websites of key commercial and advocacy organisations and specialist societies to determine the extent of these interests.
They found that industry and its lobby groups fund and influence the activities and policies of osteoporosis advocacy organisations such as the US National Osteoporosis Foundation (NOF) and the Europe based International Osteoporosis Foundation (IOF).
The commerical entities include supplements manufacturers, companies that produce vitamin D test kits, and the Council for Responsible Nutrition, which describes itself as the "leading trade association representing dietary supplement manufacturers and ingredient suppliers."
The NOF and IOF have not changed their positions to reflect the accumulating evidence, note the authors. In fact, after evidence accrued that calcium and vitamin D do not safely reduce fracture risk, "the nutrition industry continued to partner with osteoporosis advocacy organisations to promote their widespread use."
They argue that some prominent academics and specialist societies have undeclared commercial and academic conflicts of interest in the nutrition osteoporosis field.
They also point out that the National Bone Health Alliance (an offshoot of the NOF) recently advocated broadening the diagnostic criteria for osteoporosis, "which would lead to recommendations for treatment in 50% and 86% of American men and women aged over 75 years, respectively."
"Disentangling industry from academia might improve the translation of evidence into practice," conclude the authors. They suggest that the emerging requirements that drug companies declare payments to health practitioners "should be broadened to include supplements and food manufacturers."
Advocacy organisations and specialist societies "should eschew corporate sponsorship," they add, "and academics should not engage with advocacy organisations until it is clear that such commercial ties have been severed."