OMAHA, Neb. - The relationship between vitamin D and calcium and bone health continues to cause conflict among researchers, most recently with a Chinese study that found no significant link between supplements and bone fractures.
The study, described this week in the Journal of the American Medical Association, examined 33 clinical trials with 51,145 participants. The report said calcium and vitamin D supplements were “not associated with a significant difference in the risk of hip fractures” in older people.
One Creighton University scientist who has devoted much of his work to osteoporosis, bone health and vitamin D said the report will harm people. Dr. Robert Recker said nutritional studies are difficult to conduct and easy to get wrong.
Furthermore, a University of Nebraska Medical Center professor said, “there’s plenty of studies that have said the opposite” of the new report.
Recker, a Creighton professor of medicine and head of the Creighton Osteoporosis Research Center, said the report “is harmful to people’s health, and it’s going to result in fractures that might not otherwise have happened.”
Recker said vitamin D is necessary for absorption of calcium and bone formation.
The paper in JAMA is “complete bull ... if you excuse my expression. That’s going to cause a lot of harm,” Recker said.
Osteoporosis is a disease that causes bones to weaken. One in four women 65 and older suffers from it, according to the Centers for Disease Control and Prevention, as do 6 percent of men, or one in 17.
More than 300,000 Americans 65 and older are hospitalized each year with hip fractures.
Creighton scientists such as the late Dr. Robert Heaney for years have said that studies of nutrition, including vitamin D, are difficult to do.
It’s not enough to give some clinical trial participants vitamin D and others placebos because everyone gets different amounts of vitamin D from the sun and from their diets.
The new report acknowledges that some of the trials failed to test initial vitamin D blood levels for all participants.
Janet Heaney, a retired Creighton research associate, Heaney’s wife and the co-author of a Heaney book on calcium, said that when a person gets on supplements is also important.
The notion that they don’t help “is probably true if you don’t start until they’re elderly,” she said. “I think a key issue there would be when would those interventions have been done.”
Nancy Waltman, a UNMC professor of nursing, said the report is “a disservice to women.” Eighty percent of cases of severe bone loss are in women, she said.
Waltman, who has a doctorate in education, said it’s well-known that vitamin D is “the key that unlocks calcium,” and that calcium is the building block of bone.
“You’ve got to have an adequate level of calcium and vitamin D, otherwise there’s no way to build bone,” she said.
Waltman said vitamin D and calcium supplements probably aren’t enough to achieve bone health. Other factors such as exercise, good diet and smoking cessation are important. And if one has bone loss, medications (beyond supplements) probably will be necessary, she said.
Waltman has completed one federally funded study of bone loss and is in the middle of a second.
A Washington Post story on the study noted that the U.S. Preventive Services Task Force has questioned the use of calcium and vitamin D supplements. In 2013, the federal task force said evidence to support the use of supplements in senior citizens without osteoporosis or vitamin D deficiency was insufficient.
Recker said vitamin D also can lower the risk of cancer, diabetes and many other diseases. It’s best, he said, if one starts taking supplements when young — even in infancy.
This report includes material from the Washington Post.