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Tuesday, March 12, 2013

THE VIEW FROM THE OFFICE


IS CALCIUM AND VITAMIN D BAD FOR YOU?


THE USPSTF HAS JUST PUT CALCIUM AND VITAMIN D IN THE DOG HOUSE:  The USPSTF is taking abrupt action to stop this new menace--calcium and vitamin D supplementation--in its tracks.(1) Those of you who have been harmed by this pernicious combination should call 1-800-BAD-DRUG.
        Actually, we don't really know that these drugs are bad for us, it is just that there is 'insufficient evidence' to know that they're good for us, but let's not quibble. Specifically, we can say categorically that there is at present no good evidence that routine calcium and vitamin D supplementation for men or pre-menopausal women offers any benefit for the prevention of fractures. There may be other benefits but these are not discussed. The Task Force adds salt to the wound by stating 'current evidence is insufficient to assess the balance of the benefits and harms of daily supplementation with greater than 400 IU of vitamin D3 and greater than 1000 mg of calcium for the prevention of fractures in non-institutionalized postmenopausal women. For those who have ever had the misfortune to prescribe these, take 2 aspirin and call your lawyer. Finally, the emboldened USPSTF takes a strong stand ("recommends against") on daily supplementation with 400 IU or less of vitamin D3 and 1000 mg or less of calcium for the primary prevention of fractures in non-institutionalized postmenopausal women.
        The USPSTF also mentions some countervailing factors:
        1. They do recommend vitamin D supplementation (~800 IU/d) for the prevention of falls in community-dwelling adults aged 65 years and older who are at increased risk for falls because of a history or recent falls or vitamin D deficiency.
        2. A major meta-analysis of 31,022 adults over the age of 65 found that fractures may be reduced (by ~ 12%) for persons taking higher doses of vitamin  D (> 800 IU/d) among both institutionalized and community-dwelling adults.
        3. In fact, the USPSTF itself concluded in 2011 that combined vitamin D (300-1100 IU/d) and calcium supplementation (500 to 1200 mg/d), but not vitamin D supplementation alone, can reduce the fracture risk in older adults.
        4. The Institute of Medicine and World Health Organization have recommended standards for adequate daily intake of calcium and vitamin D as a part of overall health.

        I would suggest that this concern for overall health may be relevant for people in our business. Preventing falls isn't a bad thing either. Calling attention to dietary and nutritional factors in health could be construed by some as a good thing.
        The only harm that the USPSTF can dig up about supplementation is an increased risk of kidney stones (estimated number needed to harm (NNH) 1/273. Perhaps we can learn to live with this.
COMMENT: This recommendation statement is premature. When we have good authority to do something generally considered safe (e.g., IOM, WHO, and the former USPSTF) it should require some very solid evidence (not just a lack of it) to overturn established practice that could still be very health promoting despite the Task Force's cautions. A 1/273 risk of kidney stones does not rise to that level of evidence or harm. The problem with the USPSTF is increasingly that, as with Orwell's elephant, they find the evidence synthesis easier to do when inspecting only small pieces of the elephant. What we need our recommendations to be based on are some good whole-elephant outcomes.
        It its consumer-oriented report of the guidelines the USPSTF does offer this helpful aid to interpretation illustrating that their opinion should be just one of many that goes into a consumer decision about calcium and vitamin D supplementation.





        In the meantime, what do you do?
        1. Don't change current practice. There is not enough evidence to do so.
        2. At a minimum have a discussion with all patients aged 65 years or older about the prevention of falls and the possible prevention of fractures.
        3. Don't start using more alendronate (or other bisphosphonates) since benefit from these is only clear for the group of patients who have already had fragility fractures.
        4. Do temper your enthusiasm for screening for osteoporosis since it appears that we don't know what to do about it anymore.
        5. Do fall back on exercise as the main preventive measure. I would, of course, assert that we should be doing this anyway...BUT WAIT, THE USPSTF DOES NOT ENDORSE COUNSELING TO EXERCISE EITHER!(2)

SHOPPERS, IT'S SAFE TO GO NEAR THE EGGS AGAIN: Chicken eggs are high in cholesterol (about 200 mg each). It is common for providers and experts to caution against their consumption in persons for whom cholesterol is a clinical concern. We have a new meta-analysis of 17 prospective cohort studies in which egg consumption was measured with food-frequency questionnaires; patients were followed for 10 to 20 years of follow-up.(3) No associations between egg consumption and risk for either heart disease or stroke were observed. For the subgroup of diabetics, egg consumption increase the risk of heart disease (RR, 1.5) and lower the risk of stroke (RR, 0.80). COMMENT: Eat your eggs.

DIET DOES MATTERDespite the USPSTF's apparent opposition, interventions to promote a healthy diet (in this case, specifically a Mediterranean diet) have some significant benefits. We've all known about the substantial benefits of a Mediterranean diet for years. Here we have another confirmation.(3) Spanish investigators conducted a multicenter trial in which 7447 high-risk patients were randomly assigned to one of 3 interventions: (1) a Mediterranean diet supplemented with extra-virgin olive oil; (2) a Mediterranean diet supplemented with mixed nuts; or (3) a control diet. Participants received quarterly individual and group educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small non-food gifts. The primary end point was the rate of major cardiovascular events (MI, CVA, or death from CV causes). On the basis of the results of an interim analysis, the trial was stopped after a median follow-up of 4.8 years. The multivariable-adjusted hazard ratios were 0.70 and 0.72 for the group assigned to a Mediterranean diet with extra-virgin olive oil and the group assigned to a Mediterranean diet with nuts, respectively. COMMENT: This worked very nicely. How are you going to get patients to even try a nice health diet like this if you don't counsel them?  Tell me that, USPSTF!





   350
parts per million of atmospheric carbon compatible with a familiar, sustainable planet Earth



REFERENCES:

1. USPSTF. Vitamin D and calcium supplementation to prevent fractures in adults: Clinical summary of US Preventive Services Task Force Recommendation. www.uspreventiveservicestaskforce.org/uspstf12/vitamind/vitdsumm.htm. Chung M et al for the USPSTF. Vitamin D with or without calcium supplementation for prevention of cancer and fractures: An updated meta-analysis for the USPSTF. Ann Intern Med 2011; 155: 827-38. Moyer VA for the USPSTF. Vitamin D and calcium supplementation to prevent fractures in adults: US Preventive services Task Force Recommendation Statement. Ann Intern Med 2013; Feb 26.

2. USPSTF.Behavioral Counseling to Promote a Healthful Diet and Physical Activity for Cardiovascular Disease Prevention in Adults. http://www.uspreventiveservicestaskforce.org/uspstf/uspsphys.htm

3. Rong Y et al. Egg consumption and risk of coronary heart disease and stroke: Dose-response meta-analysis of prospective cohort studies. BMJ 2013 Jan 7; 346:e8539. (http://dx.doi.org/10.1136/bmj.e8539)

4. Estruch R et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med 2013 Feb 25. PMID: 23432189.