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 MATTER:
Despite
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.