Posted on 01/14/2010 10:34:31 AM PST by decimon
(SACRAMENTO, Calif.) — Taking both calcium and vitamin D supplements on a daily basis reduces the risk of bone fractures, regardless of whether a person is young or old, male or female, or has had fractures in the past, a large study of nearly 70,000 patients from throughout the United States and Europe has found.
The study included data published in 2006 from clinical trials conducted at UC Davis in Sacramento as part of the Women’s Health Initiative (WHI). It appears online in this week’s edition of the British Medical Journal.
“What is important about this very large study is that goes a long way toward resolving conflicting evidence about the role of vitamin D, either alone or in combination with calcium, in reducing fractures,” said John Robbins, professor of internal medicine at UC Davis and a co-author of the journal article. “Our WHI research in Sacramento included more than 1,000 healthy, postmenopausal women and concluded that taking calcium and vitamin D together helped them preserve bone health and prevent fractures. This latest analysis, because it incorporates so many more people, really confirms our earlier conclusions.”
Led by researchers at Copenhagen University in Denmark, Robbins and an international team of colleagues analyzed the results of seven large clinical trials from around the world to assess the effectiveness of vitamin D alone or with calcium in reducing fractures among people averaging 70 years or older. The researchers could not identify any significant effects for people who only take vitamin D supplements.
Among the clinical trial results analyzed was Robbins’ WHI research, which was part of a 15-year, national program to address the most common causes of death, disability and poor quality of life in postmenopausal women such as cardiovascular disease, cancer and osteoporosis. Those trials were primarily designed to study the effect of calcium and vitamin D supplementation in preventing hip fractures, with a secondary objective of testing the supplements on spine and other types of fractures, as well as on colorectal cancer. The results were published in the Feb. 16, 2006 edition of the New England Journal of Medicine.
Fractures are a major cause of disability, loss of independence and death for older people. The injuries are often the result of osteoporosis, or porous bone, a disease characterized by low bone mass and bone fragility. The National Osteoporosis Foundation estimates that about 10 million Americans have osteoporosis; 80 percent of them are women. Four of 10 women over age 50 will experience a fracture of the hip, spine or wrist in their lifetime, and osteoporosis-related fractures were responsible for an estimated $19 billion in health-related costs in 2005.
“This study supports a growing consensus that combined calcium and vitamin D is more effective than vitamin D alone in reducing a variety of fractures,” said Robbins. “Interestingly, this combination of supplements benefits both women and men of all ages, which is not something we fully expected to find. We now need to investigate the best dosage, duration and optimal way for people to take it.”
UC Davis Health System is an academic health center that includes a top-ranked school of medicine, a 613-bed acute care hospital, the Betty Irene Moore School of Nursing, a National Cancer Institute-designated cancer center, the unique MIND Institute for the study of neurodevelopmental disorders, a comprehensive children's hospital, a level 1 trauma center and outpatient clinics in communities throughout the Sacramento region. Consistently ranked among the nation's top medical schools and best hospitals, UC Davis has established itself as a national leader in telehealth, rural medicine, cancer, neurodevelopmental disorders, vascular medicine, and trauma and emergency medicine. Other areas of research strength include clinical and translational science, regenerative medicine, infectious disease, neuroscience, functional genomics and mouse biology, comparative medicine and nutrition, among many others.
Osteoplastery ping.
No comment on what foods have both calcium and vitamin D. Makes me think that this study was funded by companies the produce Calcium and Vitamin D supplements, either that or just a shoddy bit of reporting.
Milk, but the vitamin D is added. Fish, and fish-eating critters, usually have vitamin D but I don't know that any have calcium.
There are ways to get calcium but we're supposed to get vitamin D from sunlight. But it's difficult-to-impossible to get vitamin D from sunlight so we supplement.
Went and skimmed through the published study, looking for the amount of vitamin D dosage. Study results were based on 10ug/day of D, along with calcium supplement. That’s only 400 IU of vitamin D.
Many experts in this area of research advise up to 5000 IU daily, to avoid deficiency. At this purported optimum vitamin D dosage, the body’s usage of calcium is optimized, too, so a calcium supplement should not be needed. I’d be wary of taking calcium along with high vitamin D supplements.
Well, there's an older study of just postmenopausal women. The results are in the Feb. 16, 2006 edition of The New England Journal of Medicine. Data from that study was included in the results of this study reported in the British Medical Journal. I'm seeing dosages of more than just 400 IU of vitamin D.
Many experts in this area of research advise up to 5000 IU daily, to avoid deficiency. At this purported optimum vitamin D dosage, the body’s usage of calcium is optimized, too, so a calcium supplement should not be needed. I’d be wary of taking calcium along with high vitamin D supplements.
You may be right about amounts of calcium but you do need calcium for it to be used. That taking more vitamin D should dictate limiting calcium intake is something I would dispute. If vitamin D optimizes calcium usage then what is the best amount of calcium to take should be independent of the amount of vitamin D.
Thank you for your reply, and heavens no, I’m not suggesting reducing calcium.
Rather, I suspect that the RDA for vitamin D is too low, perhaps by an order of magnitude. If our skin can produce 10,000 IU of D with just half an hour of strong sunlight, then I don’t believe larger (1000 to 5000 IU) of supplementation advised by some vitamin D researchers could be toxic. One of the (few) reasons given for not taking larger doses of D is that calcium levels in the body can get too high, leading to problems like kidney stones. However, other researchers point out that this condition only develops if calcium supplements are taken along with the larger dose of vitamin D. I was only referring to taking a calcium supplement in the context of taking large amounts of D, not the 10 or 20 ug/day used in the study. My suspicion is that in the study, 400 to 800 IU of D may be too low to show solid benefits, unless aided by a calcium supplement.
I recall my dad had a bad bout of kidney stones, at a younger age than I am now. Before beginning a vitamin D supplement, I did some research into possible side effects. I’ll avoid a calcium supplement, my usual dietary intake (I like dairy) should be sufficient.
The only other supplement I take is fish oil, and there is some interesting synergy (to me,anyway) in how the body uses omega 3 and vitamin D, not necessarily calcium. The US has just begun a five-year study of both omega 3 and vitamin D supplements, with 20,000 people, but I’m not waiting for the results, I’m trying it on my own.
That was in the findings of the first linked study of postmenopausal women. But the particulars of the thing are too far beyond me. One thing I noticed in that study is that they supplemented with calcium carbonate. The claim has been that the calcium in calcium citrate is much more absorbed than the calcium in calcium carbonate.
So, does that have anything to do with developing kidney stones? I have no idea. I post these articles for whom they may help and leave them to their own research.
We pre-specified the following study level variables for entry into this interaction analysis: vitamin D daily dose equivalent, route (oral or intramuscular), and co-administration of calcium. We then used variables that interacted significantly to stratify the subsequent fixed effects Cox fracture-free survival analysis, which contained a series of dummy variables to capture residual differences in risk of fracture between trials. A subgroup analysis by dose (10 µg/day v 20 µg/day) was pre-specified. We thus classified the Meyer, Larsen, and Women’s Health Initiative (WHI) studies as 10 µg studies and classified the Smith study (equivalent to 20.5 µg/day), the Lyons study, the RECORD study, and the Porthouse study (all equivalent to 20 µg/day) as 20 µg studies. Observations were truncated after 36 months; only the WHI study provided sufficient patients to populate the analysis beyond this.
BRAVO!!! Thank you for finding the original article.
That's a puny amount of vitamin D. Or is it? Converting micrograms, µg, of vitamin D to international units(IU) says 10 µg equals 400 IU. That's the smallest vitamin D supplement that I've seen.
Look up opening a link in a new window.
It helps me posting and following an argument.
You can’t tell if a link opens in a new window so I right-click them and open them, usually, in a new tab.
What's a tab?
Ehh, what's up, doc? A tab is to a window as osteopathy is to medical practice.
If you're serious then the help feature of your browser will best explain what is a tab and what is a window. Or the Wikipedia entry: Tab.
Thank you.
No, thank you. I post more than I can understand and you help keep it straight.
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