An intricate web of interactions between industry, advocacy organisations, academics and specialist societies needs to be broken to ensure clinicians receive accurate guidance about calcium and vitamin D supplementation to prevent osteoporosis, two Auckland endocrinologists have claimed.
Associate Professors Andrew Grey and Mark Bolland said that clinical guidelines around the world have been very successful in encouraging supplementation, but they do not reflect evidence emerging since 2002 that it fails to reduce the risk of fracture and may result in harm.
“Over half of older Americans take calcium and vitamin D supplements, and bone health is the most common specific motivation,” they said.
“Increased calcium and vitamin D intake should not have been recommended for older adults living independently after 2007.”
Writing in the BMJ, they said worldwide sales of calcium supplements total about $6 billion annually, and vitamin D sales amount to $750 million in the United States alone.
Other beneficiaries of the focus on calcium and vitamin D include the food industry, for example through products like calcium-enriched milk, as well as pathology laboratories which measure vitamin D and the suppliers of the assays.
“The nutrition industry influences research that affects its products,” Grey and Bolland said.
“It funds research, presumably hoping that the outcomes will support the use of its products, and sponsors meetings at which prominent academic speakers advocate nutritional supplements.”
Support of advocacy organisations such as the International Osteoporosis Foundation is a more insidious form of influence.
Industry, advocacy organisations, specialist societies and academics all benefit from their complex mutual relationships.
“The party that may lose, and be harmed, is the public,” they said.
“Improving transparency of the interactions…is desirable, but reducing those interactions is more so.
“The emerging requirements that drug companies declare payments to health practitioners should be broadened to include supplements and food manufacturers.”
Osteoporosis Australia guidance on calcium and vitamin D supplementation, updated in June 2015, cites studies showing that it reduces fracture risk in older people with low calcium and vitamin D intakes.
Ideally, the recommended dietary intake (RDI) of calcium should be achieved by consuming a diet rich in calcium but, if not, a daily supplement of 500-600 mg is indicated.
Vitamin D supplements are appropriate in many older people with any degree of vitamin D deficiency.
“Taken as recommended, combined calcium and vitamin D supplements remain both safe and effective for the majority of people at high risk of fracture, especially ageing women,” the guidance states.