Posted on 02/15/2006 6:52:24 PM PST by Pharmboy
The biggest study ever of calcium and vitamin D supplements for older women showed they offered only limited protection against broken bones, raising questions over what has been an article of faith among doctors and nutritionists.
The supplements seemed to reduce the risk of broken hips in women over 60 and also helped those who took the supplements most regularly. But as to preventing bone fractures overall, vitamin D and calcium flunked in these healthy women.
One of the researchers, Dr. Norman Lasser at New Jersey Medical School, said the study is "not as ringing an endorsement of calcium as one might like."
Even so, many experts said they would stand behind federal guidelines recommending the supplements, if needed, to meet standard intake of calcium and vitamin D.
"There's probably a small benefit," said Dr. Joel Finkelstein, of Massachusetts General Hospital, who wrote an editorial in the New England Journal of Medicine where the study appeared Thursday. "It's a good start, but women at higher risk need to know it's not enough."
The findings were an offshoot of the big national study of diet and hormone therapy known as the Women's Health Initiative.
Osteoporosis touches an estimated 10 million Americans, making their bones prone to break. One of two women will suffer such a fracture in her lifetime.
For women over age 50, federal guidelines recommend 1,200 milligrams of bone-building calcium and 400-600 international units of vitamin D daily from diet and, if needed, supplements.
The seven-year study of 36,282 women ages 50 to 79 gave half the participants 1,000 milligrams of calcium and 400 units of vitamin D, while the other half took dummy pills.
However, many were also taking their own supplements before the research began, and they were allowed to keep doing so, whether they were assigned to the test group or the comparison group. These extra supplements may have helped the women stay healthy but ironically diluted the findings, since any benefit is harder to show against a backdrop of fewer fractures. Also, women in the study were taking hormone pills, likely further cutting the number of fractures.
The study showed better hip bone density in the group given supplements, but they ranked no better statistically in avoiding fractures of all kinds. However, women over age 60 reduced their chances of hip fracture by 21 percent with the supplements.
Many women sometimes missed their daily dose — a common phenomenon in real-world testing — but those who took their supplements most faithfully lowered their risk by 29 percent.
"We still do believe ... that maintaining an adequate calcium intake will lay the foundation for bone health," said lead author Dr. Rebecca Jackson at Ohio State University.
Dr. Bess Dawson-Hughes, a Tufts University vitamin expert who helped shape the dietary guidelines, said they should remain unchanged for now. She largely dismissed the overall negative finding.
"You put people who don't need it together with people who aren't taking it, and you find nothing — and that really isn't all that surprising," she said.
Some researchers said the effect would have been clearer with higher doses of vitamin D, perhaps up to 1,000 units daily. The vitamin helps the body absorb calcium and promotes muscle health, reducing falls.
"We don't want to send the message to people to throw away their calcium pills, which was my wife's first reaction," said Lasser, one of the study authors.
The study did show a significant side effect with the diet supplements: a 17 percent increase in the risk of kidney stones. But several doctors downplayed that risk, saying hip fractures are typically much worse than kidney stones.
Doctors said the study suggests that women at higher risk of fracture — whose tests show lost bone density — likely need more than diet supplements. They may require osteoporosis drugs.
The study also checked whether the supplements might help prevent colon cancer, and the results indicated there was no benefit. That wasn't a big surprise partly because past studies had not signaled much benefit.
Still, the researchers plan to check participants in future years, because colorectal cancer can take 10 to 20 years to develop.
___
On the Net:
New England Journal of Medicine: http://nejm.org
federal dietary guidelines:
http://www.health.gov/dietaryguidelines/dga2005/document/html/chapter2.htm
Osteoporosis facts:
http://www.osteo.org/newfile.asp?docfast&doctitleFast+Facts+on+Osteoporosi
&doctypeHTML
If I forget my calcium supplements for a few days, I get leg cramps. The cramps go away immediately after taking calcium.
I've always wondered the association of drinking sodas and obesity.
I gave up Coca Cola after going through a few bouts of severe headaches, along with vomiting upon withdrawal from the normal amount of Coke.
Since then, I lost some weight and have not gained it back in spite of not changing my eating habits. I also get plenty of calcium. I love ice cream. It's my treat.
Vitamin D is toxic in large doses, did your doctor approve that amount?
Calcium absortipn from the gut is mainly determined by the amount of active vitamin D in your blood.
Sato Shines a Light on Sunshine
Bess Dawson-Hughes
Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts, USA Commentary on: Sato Y, Iwamoto J, Kanoko T, Satoh K. Amelioration of osteoporosis and hypovitaminosis D by sunlight exposure in hospitalized, elderly women with Alzheimer's disease: a randomized controlled trial. J Bone Miner Res. 2005 Aug;20(8):1327-33.
Sato and colleagues (1) have demonstrated that improving vitamin D status can lower risk of fracture. A modest amount of sun exposure, averaging about 10 minutes per day to the face, arms, and hands, dramatically increased serum 25-hydroxyvitamin D [25(OH)D] levels. Results showed, at the end of one year, the mean serum 25(OH)D concentration was 52.2 ng/ml in the sun exposed group and 10 ng/ml in the control group. This rise in serum 25(OH)D also induced several changes along the metabolic bone pathway, including an increase in serum calcium, and a decrease in each of the following: serum parathyroid hormone, biochemical markers of bone turnover, and rates of metacarpal bone loss. Sun exposure also improved lower extremity muscle performance and lowered risk of falling.
These actions most likely resulted from the activation of vitamin D receptors in muscle tissue, along with the promotion of the size and number of the type 2 muscle fibers (2). The combination of the reduction in bone loss and fewer falls then led to significantly fewer fractures, in the sun-exposed group.
In the trial conducted, both the control and sun exposure groups were given 1,200 mg/d of calcium. Thus, the biochemical and clinical improvements in the sun exposed group can clearly be attributed to improved vitamin D status. While calcium is no antidote to vitamin D deficiency, the benefit from sun exposure in this study was realized in the calcium replete subjects. Therefore, one cannot conclude that the benefit observed with the increased serum 25(OH)D levels would have been the same in calcium deficient subjects.
The population studied by Sato and colleagues was at very high risk for vitamin D deficiency as determined by its combination of low dietary intake of the vitamin (<100 IU per day), and the minimal amount of time it habitually spent out of doors. Most of these patients were undoubtedly osteomalacic; as such, it would have been interesting to know their serum alkaline phosphatase levels.
Vitamin D supplementation has been evaluated in a series of different studies of older men and women (3-7). In one or more of these studies, supplementation with 700 to 800 IU per day of vitamin D3, with and without added calcium, has raised serum 25(OH)D, and has lowered PTH, biochemical markers of bone turnover, and rates of bone loss (3;4).
Vitamin D also improved muscle performance in the lower extremities (5), reduced risk of falling (6), and lowered risk of fracture (7).
The study by Sato, however, is the only vitamin D intervention trial to document significant changes in each of the measures shown in Figure 1. This is likely because the Alzheimer's patients studied had a more profound degree of deficiency at the beginning of the trial than subjects in the other studies. It is generally accepted that the benefit of a given nutritional replacement is directly proportional to the degree of deficiency characteristic of the recipient.
This study underscores the point that a small amount of sun exposure on a regular basis will raise and maintain the serum 25(OH)D at the appropriate level. This is true in elderly subjects, despite the fact that they have a reduced capacity of vitamin D production in skin (8). The Sato study took place at 32 degrees latitude (similar to that of Sydney, Cape Town, Buenos Aires, Cairo, San Diego, and Jacksonville). From the previous work of Webb, it is known that sun exposure promotes vitamin D production year round, at this latitude (9).
At higher latitudes, however, vitamin D synthesis in skin becomes more restricted during the wintertime. For example, at latitude of 42 degrees (Boston, Chicago, Rome, Beijing), little to no production takes place between mid-October and mid-March (9). At still higher latitude of 52 degrees (Edmonton, Liverpool, Moscow, Punta Arenas), vitamin D production takes place only for 4 or 5 months of the year (9). Thus, being out of doors for 10 minutes per day year round will not be as effective for those who live at higher latitudes.
An alternative to natural sun exposure is the use of sun lamps for several minutes per day. We and others have successfully used this approach in patients who do not have normal vitamin D absorption. Perhaps this should, as previously proposed, be considered as an alternative to natural sun exposure for residents of nursing homes and other institutionalized individuals. Sato has reminded us of the consequences of ignored vitamin D deficiency and has also demonstrated an effective, low-cost and safe approach to correcting it.
Footnotes
Conflict of Interest: The author reports that no conflict of interest exists.
References 1. Sato Y, Iwamoto J, Kanoko T, Satoh K. Amelioration of osteoporosis and hypovitaminosis D by sunlight exposure in hospitalized, elderly women with Alzheimer's disease: a randomized controlled trial. J Bone Miner Res. 2005 Aug;20(8):1327 -33.[Medline] 2. Sorensen OH, Lund B, Saltin B, Lund B, Andersen RB, Hjorth L, Melsen F, Mosekilde L. Myopathy in bone loss of ageing: improvement by treatment with 1 alpha-hydroxycholecalciferol and calcium. Clin Sci (Lond). 1979 Feb;56(2):157 -161.[Medline] 3. Chapuy MC, Arlot ME, Duboeuf F, Brun J, Crouzet B, Arnaud S, Delmas PD, Meunier PJ. Vitamin D3 and calcium to prevent hip fractures in the elderly women. N Engl J Med. 1992 Dec 3;327 (23): 1637-42.[Abstract] 4. Dawson-Hughes B, Harris SS, Krall EA, Dallal GE. Effect of calcium and vitamin D supplementation on bone density in men and women 65 years of age or older. N Engl J Med. 1997 Sep 4;337(10): 670-6.[Abstract/Free Full Text] 5. Pfeifer M, Begerow B, Minne HW, Abrams C, Nachtigall D, Hansen C. Effects of a short-term vitamin D and calcium supplementation on body sway and secondary hyperparathyroidism in elderly women. J Bone Miner Res. 2000 Jun;15(6):1113 -8. Erratum in: J Bone Miner Res. 2001 Oct;16(10):1935; J Bone Miner Res. 2001 Sep;16(9):1735.[Medline] 6. Bischoff-Ferrari HA, Dawson-Hughes B, Willett W, Staehlin H, Bazemore M, Zee R, Wong J. Effect of vitamin D on falls: a meta-analysis. JAMA. 2004 Apr 28;291(16):1999 -2006.[Abstract/Free Full Text] 7. Bischoff-Ferrari HA, Willett W, Wong JB, Giovannucci E, Dietrich T, Dawson-Hughes B. Fracture prevention with vitamin D supplementation: a meta-analysis of randomized controlled trials. JAMA.2005 May 11;293(18):2257 -64.[Abstract/Free Full Text] 8. MacLaughlin J, Holick MF. Aging decreases the capacity of human skin to produce vitamin D3. J Clin Invest.1985 Oct;76(4):1536 -8.[Medline] 9. Webb AR, Kline L, Holick MF. Influence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin. J Clin Endocrinol Metab. 1988 Aug;67(2): 373-8.[Abstract]
My favorite anecdotes are the women who take calcium supplements only to watch their fingers get calcium deposits in those joints coupled with serious pain. Going off the calcium = no pain.
Yep...
Calcium without magnesium is NO help.
That's why I have a wife. To fetch things for me. (Gawd, I hope she doesn't read this.)
YES, my doc approved that....and talked about limits....I get evaluated every 3 months.
Plus, I live in NW Washington State.....
The entire "vitamin D is toxic" thing has been hugely overrated.
Half an hour in full sun will give you over 10,000 units of vitamin D, and if it was poisonous, dead mailmen and milkmen would be lining the streets.
The announcement that came out in Dec all but called Vitamin D deficiency a "public health emergency". Vit D is a hormonal growth regulator that aids the division of cells and the synthesis of protein. Without enough of it, the errors accumulate when the DNA is transcribed.
The December study showed Vitamin D to have a dramatic effect on the rated of colon, prostate, and breast cancer. But when you read the studies a bit more closely, you find out that the ONLY cancers they ran the rate comparisons on were those three. So it may very well have a dramatic effect on other cancers, but they weren't looking at the other types!
Hmm. I wonder how my bones will be at old age. I have cereal for breakfast almost everyday, and I ALWAYS drink all the milk (and I like soggy cereal, so I fill up the bowl). Also, I usually have a glass of milk (and chocolate milk. :3 ) or 2 a day.
I wonder...hmm.
All I need to do now is lose weight. (stares at his 221 lb. body) I MUST RUN! (heads to the treadmill)
IMHO, it doesn't do someone any good to strengthen their bones with vitamins, if they aren't also strengthening the muscle. :) Former runner, I know a little about it.
Surely you're kidding??
"I once read a study that suggested that calcium supplements cause your blood calcium to rise, and so your body says "uh-oh too much calcium!", and then proceeds to remove it... mainly by removing it from your bones, thus having the exact opposite effect that you wanted."
Actually, it's pretty much the opposite.
When the blood calcium gets low, the body starts to break down the bones to replace the low levels in the blood. That's because the blood levels of calcium are way more important to short-term survival than the bone calcium.
If that question was directed to me, check comment# 9 IIRC, on the Vitmain E and aspirin thread.
I used to work for Tennessee Corp., which was a major supplier of micronutrients (they called them trace elements). The major ones were copper, zinc, manganese and iron. Other micronutrients usually accompanied the major ones.
Major quantities of fertilzer were applied as bulk blends of small pellets. Based on soil analysis, the farmer asked for a quantity of fertilizer of a specific N-P-K analysis, with specific micrnutient addition.
An the N-P-K pellets were blended in a mixer, micronutrient powders were added to coat the pellets.
The TVA (Tennessee Valley Authority) at their Fertilizer Research Facility in Alabama once researched adding Sulfur powder to fertilizer pellets. This was to replace sulfur usually washed from the air by rain, since acid rain concerns were causing chemical and power plants to reduce sulfur emmissions.
So, replacement of minerals has been a big business for a long time.
Impact sports, such as tennis, are the best for building bone density. But if you can't participate in those for whatever reason, then make a habit of stomping around the house once a day, beat the rugs, etc.
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