by Marion Nestle

Currently browsing posts about: Supplements

Feb 26 2013

Supplements? Advice about Calcium and Vitamin D vs. Osteoporosis

Malden Nesheim and I wrote an editorial for the Annals of Internal Medicine that has just gone online, and is likely to elicit plenty of discussion.  We comment on the highly conservative, evidence-based recommendations of the U.S. Preventive Services Task Force for taking supplements of calcium and vitamin D as a means to prevent osteoporosis.

Our commentary: “To Supplement or Not to Supplement: U.S. Preventive Services Task Force Recommendations on Calcium and Vitamin D.”  Here’s what we said:

In this issue, the U.S. Preventive Services Task Force (USPSTF) plunges headlong into ongoing debates about whether healthy adults—those who show no signs of vitamin D deficiency or osteoporosis—should be advised to take combined supplements of calcium and vitamin D to prevent bone fractures and, if so, at what level (1).

In terse statements unlikely to settle the debates, the Task Force states first that insufficient evidence makes it impossible to determine how supplementation affects fracture incidence in men or premenopausal women. Next, it deals with postmenopausal women. For this group, the Task Force says that evidence is insufficient to assess the effects of daily supplementation with greater than 400 IU of vitamin D3 and greater than 1000 mg of calcium. The Task Force’s unambiguous conclusion: Supplementation at or below those levels does not prevent fractures. Because supplementation at or below 400 IU of vitamin D3 and 1000 mg of calcium seems to convey a slightly increased risk for renal stones, the USPSTF recommendation for postmenopausal women is also unambiguous: “do not supplement.”

The Task Force based these decisions on 2 commissioned evidence reviews and a meta-analysis  (2 – 4). More recent data from the Women’s Health Initiative also are consistent with inconclusive findings, except among a subgroup of long-adherent supplement recipients who experienced a reduced risk for hip—but not total—fractures (5).

The Task Force’s recommendations must be interpreted in the light of ongoing disputes about the most effective method for assessing vitamin D deficiency, whether calcium and vitamin D supplements are needed by a large portion of the population, and what level of supplementation might best maximize benefits and minimize risks.

In 2011, after reviewing more than 1000 studies, the Institute of Medicine (IOM) concluded that vitamin D and calcium are indeed critical to bone health but their role in other diseases—cancer, heart disease, diabetes, immune function, and reproductive health, for example—remains uncertain. The IOM did not consider deficiencies of either calcium or vitamin D to be serious problems in the United States, except among certain population groups. Instead, because of widespread fortification and supplementation, the IOM was concerned about the possibility of adverse consequences from oversupplementation (6).

With risks as well as benefits in mind, the IOM established the average adult daily requirement for calcium at 800 to 1000 mg depending on age, the Recommended Dietary Allowance (the amount needed to meet the needs of about 97% of the population) at 1000 to 1200 mg, and the safe upper level of intake at 2000 to 2500 mg. Its corresponding recommendations for vitamin D were 400 IU, 600 IU (800 IU for older adults), and 4000 IU, respectively. The IOM viewed these levels as sufficient to maintain blood levels of 25-hydroxyvitamin D at or above 20 ng/mL, a level it considered adequate to meet population-based needs regardless of amounts synthesized as a result of sun exposure.

Vitamin D, of course, is not a vitamin in the usual sense. It is a hormone produced in response to the action of sunlight on skin. Like other hormones, vitamin D has multiple roles in the body, not all of them well-understood. Vitamin D supplementation, therefore, must be considered a form of hormone replacement therapy. As such, it raises all of the questions about efficacy, dose, and side effects currently asked of such therapies.

In that light, the 2011 recommendations of the Endocrine Society deserve special scrutiny (7). The Society approaches questions about vitamin D from a standpoint quite different from that of the IOM. It appointed its own task force to make recommendations based on the premise that vitamin D deficiencies are common among all age groups. The Society prefers 30 ng/mL of 25-hydroxyvitamin D as the target level for maximum benefits. By that criterion, virtually all U.S., Canadian, and European adults are deficient in hormone vitamin D and require daily supplements of 1500 to 2000 IU. For adults with demonstrated deficiency, the Society recommends treatment with 50 000 IU of the hormone once a week or daily supplementation of 6000 IU for 8 weeks, followed by 1500 to 2000 IU for maintenance.

This clinical endocrinology perspective differs from the nutrition science perspective of the IOM committee, whose members tend to interpret studies of single nutrients within the context of the diet as a whole. From this standpoint, the amount of hormone generated by the action of sunlight on skin (which ought to be more than adequate for people who spend time outdoors in latitudes as far north as Boston) is crucial to decisions about supplementation. The IOM and Endocrine Society debated their conflicting perspectives in an exchange published in 2012 (8 – 9). The insufficiency of research to resolve such arguments has permitted vitamin D to become “trendy.” It is advertised on boxes of fortified cereals, has its own prosupplement advocacy group, and generates millions in annual supplement sales (10).

The USPSTF’s recommendations can be understood as an attempt to clarify the present situation with respect to one specific outcome of supplementation. In doing so, its recommendations have a substantial advantage. They depend on hard end points—fractures—rather than on blood levels of 25-hydroxyvitamin D, at best an indirect measure of vitamin D adequacy. The USPSTF uses the same precautionary approach as did the IOM. In the absence of compelling evidence for benefit, taking supplements is not worth any risk, however small.

A previous attempt to sort through the various claims for vitamin D noted an urgent need for further research to answer fundamental questions about the risks and benefits of sun exposure, fortification, and supplements, and the hormone’s role in body functions beyond bone mineralization (11). The USPSTF plans to publish further recommendations on the role of vitamin D in cancer prevention. When it does, we hope it will keep in mind the value of making a single recommendation about vitamin D and calcium supplementation that will encompass all potential benefits and risks. Multiple recommendations by condition confuse practitioners and the public. While we wait for the results of further research, the USPSTF’s cautious, evidence-based advice should encourage clinicians to think carefully before advising calcium and vitamin D supplementation for healthy individuals.

References

1  Moyer VA; U.S. Preventive Services Task Force.  Vitamin D and calcium supplementation to prevent fractures in adults: U.S. Preventive Services Task Force Recommendation Statement. Ann Intern Med. 2013. [Epub ahead of print]

2  Cranney A, Horsley T, O’Donnell S, Weiler H, Puil L, Ooi D, et al.  Effectiveness and safety of vitamin D in relation to bone health. Evid Rep Technol Assess (Full Rep). 2007:1-235. [PMID: 18088161]

Chung M, Balk EM, Brendel M, Ip S, Lau J, Lee J, et al.  Vitamin D and calcium: a systematic review of health outcomes. Evid Rep Technol Assess (Full Rep). 2009:1-420. [PMID: 20629479]

Chung M, Lee J, Terasawa T, Lau J, Trikalinos TA.  Vitamin D with or without calcium supplementation for prevention of cancer and fractures: an updated meta-analysis for the U.S. Preventive Services Task Force. Ann Intern Med. 2011;155:827-38. [PMID: 22184690]

Prentice RL, Pettinger MB, Jackson RD, Wactawski-Wende J, Lacroix AZ, Anderson GL, et al.  Health risks and benefits from calcium and vitamin D supplementation: Women’s Health Initiative clinical trial and cohort study. Osteoporos Int. 2013;24:567-80. [PMID: 23208074]

Institute of Medicine.  Dietary Reference Intakes: Calcium, Vitamin D. Washington, DC: National Academies Pr; 2011.

Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al; Endocrine Society.  Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96:1911-30. [PMID: 21646368]

Rosen CJ, Abrams SA, Aloia JF, Brannon PM, Clinton SK, Durazo-Arvizu RA, et al.  IOM committee members respond to Endocrine Society vitamin D guideline. J Clin Endocrinol Metab. 2012;97:1146-52. [PMID: 22442278]

Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al.  Guidelines for preventing and treating vitamin D deficiency and insufficiency revisited. J Clin Endocrinol Metab. 2012;97:1153-8. [PMID: 22442274]

10 Supplements stand out as 2008 sales bright spot for U.S. nutrition industry. Vitamins: D still shines. Nutrition Business Journal. 2009;14(6/7):5. Accessed athttp://newhope360.com/research-and-insights/supplements-stand-out-2008-sales-bright-spot-us-nutrition-industry on 15 February 2013.

11 Brannon PM, Yetley EA, Bailey RL, Picciano MF.  Overview of the conference “Vitamin D and Health in the 21st Century: an Update”. Am J Clin Nutr. 2008;88:483S-490S. [PMID: 18689388]  

Here’s the first objection:

Jan 28 2013

Some views on vitamin supplements, mostly from their makers

NutraIngredients.com reports frequently on current research and opinion on dietary supplements.  Lots of people take these products and swear by them, but proving that they do much good is another matter.  It has been hard to find evidence that they make healthy people—those who take them most often—any healthier.

Here are some recent NutraIngredient reports on this topic, largely reflecting views of the supplement industry.

Oct 23 2012

Multivitamins prevent cancer (maybe), sell supplements (definitely)

According to a new study in JAMA, multivitamins might reduce the risk of some cancers, although not by much.

But even a tiny benefit, restricted to skin cancers in healthy male doctors—but not prostate cancers, alas—is good news for the supplement industry.  Supplement sellers are eager to make sure you don’t miss this research.

The study results came out on October 18.  Pfizer, the maker of the Centrum Silver pills used in the study, placed this ad in the New York Times on October 19:

But that’s not all.  CVS pharmacy sent me this personal e-mail message:

Pfizer, of course, could not be happier.

Why do I think this is about marketing, not public health?

May 29 2012

The latest battle in the supplement wars: FDA v. DMAA

Welcome to the largely unregulated universe of dietary supplement marketing, in this case of DMAA, a.k.a. 1,3-dimethylamylamine, methylhexanamine, or geranium extract (from which it is supposedly isolated).
DMAA is supposed to stimulate athletic performance.
In April, the FDA sent letters warning ten DMAA distributors that it considered their products adulterated because:
  • DMAA does not naturally come from a food.
  • Most of it is produced synthetically
  • It might not be safe.
The FDA received 42 complaints of adverse events associated with taking DMAA supplements.  Although the reports do not prove that DMAA caused the problems, these are serious: cardiac disorders, nervous system disorders, psychiatric disorders, and death.The FDA says:

dimethylamylamine narrows the blood vessels and arteries, which increases cardiovascular resistance and frequently leads to elevated blood pressure. This rise in blood pressure may increase the work of the heart such that it could precipitate a cardiovascular event, which could range from shortness of breath to tightening of the chest and/or a possible myocardial infarction (heart attack).

One FDA warning letter went to a company called Muscle Warfare for its DMAA supplement “Napalm” which “produces intense sensations of power, drive, energy, focus, motivation, and awareness.  Enormous strength, speed and endurance increases may result.”

Here’s how the company says Napalm works:

Upon ingestion, energy is almost instantly kicked in with Air Strike while core body heat is dramatically supported. This extra body heat may then dramatically support the release of heat shock proteins, during your workout by way of our patent pending Thermobraic Heat Shock Protein Deployment System via Myobolic-SERMS/1&2….Muscle Pumps are fueled via a remarkable creatine free, Plasma Scorch Muscle Engorgement Agent….

Just pure power and dry hard size. Anabolism is kicked in by your ultra-intense workout coupled with our powerful mTOR pathways inducing Vaso-Anabolic Branched Chain Amino Acid Blend. Further hormonal anabolic support is induced by our patent pending NMDA™ hormonal support agent. NMDA™ specifically targets growth hormone, testosterone, IGF-1 and IGF-2 release and has been scientifically shown to provide dramatic support!

As I keep saying, you can’t make this stuff up.

The supplement industry, ever eager to find an athletic supplement that everyone will want to take has reacted with outrage to the FDA’s warning letters (see NutraIntredients-USA.com for a series of articles on DMAA).

Since Congress passed the Dietary Supplement Health and Education Act (DSHEA) in 1994, the supplement industry has gotten a virtually free pass on regulation and its less scrupulous members push the limits of marketing to the point where the FDA has no choice but to act.

DMAA supplement marketers now argue that if DMAA comes from geraniums, synthetic DMAA should be legal. 

I had no idea people were eating geraniums, but never mind.  The flowers may not contain DMAA anyway.

According to NutraIngredients, most DMAA is synthetic (hence: not natural):

There is only one study repeatedly referenced to show that DMAA is a naturally occurring constituent of geranium oil (Ping, Z.; Jun, Q. & Qing, L. (1996), ‘A Study on the Chemical Constituents of Geranium Oil, Journal of Guizhou Institute of Technology 25 (1): 82–85) – which analytical testing experts contacted by NutraIngredients-USA say is “not scientifically defensible“.

The supplement industry views the warning letters as signs that the FDA is going to start giving its products greater scrutiny.

That would be a step in the right direction, but maybe the FDA won’t have to.  The warning letters elicited a flood of  class action lawsuits against DMAA.

If the FDA won’t or can’t act, lawyers will take up the burden of regulating potentially unsafe and misleadingly marketed supplements.

Update, June 29:  Oops.  Investigators fail to find DMAA in geranium extracts or oils. 

Apr 10 2012

Nutritionist’s Notebook: Caffeine Cravings

On Tuesdays, I answer questions about nutrition in NYU’s student newspaper, the Washington Square News.   These appear intermittently on the newspaper’s website.  Today’s is about caffeine.

Question: What kind of effect does caffeine have on our metabolism and general health? What is an appropriate amount of caffeine to have? And are certain sources of caffeine better than others? 

Answer: Caffeine is a mild upper. It perks up your central nervous system and makes you feel more alert, energetic and cheery. Caffeine is common in plants, but coffee, chocolate and tea have the most. The amount of caffeine depends on the type, amount used and brewing time, from 30 milligrams for a small cup of weak tea to more than 300 milligrams for some of the larger and stronger Starbucks drinks. When caffeine appears on the labels, you know exactly how much you are getting.

Energy drinks made for adults, like Red Bull, contain about 80 milligrams in an eight-ounce can. Coca-Cola, Pepsi-Cola and other soft drinks marketed to children have much less — 30 to 40 milligrams in 12 ounces.

People react to caffeine in different ways and, by this stage in your life, you undoubtedly know how much of it you can handle and at what time of the day you can handle it. If you take in more than your personal limit, you may feel nervous, shaky and sleepless. The more caffeine you drink, the more you become accustomed to it and the harder it is to give up. Some researchers think that the mix of sugar with caffeine is what makes some people feel addicted to soft drinks.

Perhaps it’s the caffeine in coffee that makes researchers want to find something wrong with it. I have a thick file of papers claiming that coffee raises the risk for heartburn, cancer, heart disease, infertility, ulcers and many other health problems, but the observed effects are small, inconsistent and unconvincing. When given as a drug, caffeine stimulates urine production and suppresses appetite, but the amounts in all but the strongest coffees are too low to produce such effects. If you get shaky when you drink caffeinated beverages, it’s time to stop.

—A version of this article appeared in the Tuesday, April 10 print edition. Marion Nestle is a contributing columnist. Email her questions at dining@nyunews.com.

Additional note on the food politics of caffeineSenatorDick Durbin (Dem-IL) has just asked the FDA to enforce its own rules on drink labeling.  Some makers of high-caffeine “sports” drinks are marketing them as dietary supplements to avoid having to adhere to FDA rules on how much can go into soft drinks.

Nov 30 2011

Report from the EU: functional foods, supplements, health claims


Sebastián Romero Melchor writing in Food Chemical News (subscription required, alas) a few days ago points out that the market for functional foods in the European Union is growing.  He advises U.S. firms who want to take advantage of  its €40 billion (equal to roughly $54 billion USD) market to pay attention to some important facts:

  • Novel ingredients: Ingredients that were not consumed to a significant extent in the EU before May 15, 1997 must undergo a costly and lengthy authorization procedure so dreadful that most companies give up and choose not to include them.
  • Supplements: The European Commission has no problem with vitamins and minerals, but marketing of food supplements and fortified foods remains subject to each European country’s separate national laws.  Products legally marketed and/or manufactured in a member-state can be legally marketed throughout the EU, provided that they are (a) safe, (b) not novel, and (3) not medicinal.
  • Health claims: The European Food Safety Authority (EFSA) has issued opinions on health claims for most substances.  It has evaluted about 2,750 petitions for health claims but only approved about 600.

If only the FDA would take as rigorous a stance.

Oct 13 2011

Alas, vitamin supplements

Two studies released this week provide additional evidence that vitamin supplements are potentially harmful and, at the very least, do no good.

This depressing news comes from the Iowa Women’s Health Study.  Older women in the study who took supplements ranging from multivitamins to high doses of single nutrients had a greater risk of dying than those who did not.

Equally depressing are the results of a trial of high-dose vitamin E and selenium versus prostate cancer.  It found higher rates of the cancer among men taking vitamin E (selenium was somewhat protective).   In this trial, it was so obvious that the supplements did not protect against prostate cancer that the investigators ended it before its scheduled date of completion.

USA Today interviewed me and Dr. Jeffrey Blumberg (Tufts University) about our interpretations of these trials.

I think that the main conclusion to be drawn from this research is that supplements do not make healthy people healthier.   They may not cause harm at high doses, but they appear not to do good.

I don’t take them and I don’t recommend them—except to people who have diagnosed nutrient deficiencies or other problems handling nutrients.

Dr. Blumberg, in contrast, thinks multivitamins constitute a useful nutrition insurance policy and everybody should be taking them.

Supplements are a good example of how scientists can interpret research in different ways, depending on point of view.  I illustrate this point in Food Politics in a table in which I compare what I call “belief-based” (for lack of a better term) and “science-based” approaches to deciding whether supplements are needed, effective, or safe (see table 29, page 232).

For example, on the need for supplements, a belief-based approach rests on:

  • Diets do not always follow dietary recommendations.
  • Foods grown on depleted soils lack essential nutrients.
  • Pollution and stressful living conditions increase nutrient requirements.
  • Cooking destroys essential nutrients.
  • Nutrient-related physiological functions decline with age.

A science-based approach considers:

  • Food is sufficient to meet nutrient needs.
  • Foods provide nutrients and other valuable substances not present in supplements.
  • People who take supplements are better educated and wealthier: they are healthier whether or not they take supplements.

The statements in both approaches are true.

This is why point of view is such an important consideration in interpretation of nutrition research.

May 15 2011

Foods with benefits? Oh, please.

Sunday’s New York Times has not one but two articles about “functional foods,” those with something added over and above what’s in the food in the first place.

A front-page story, “Dessert, laid-back and legal,” describes brownies.  No, not brownies laced with marijuana.  This time they contain the sleep-inducing drug melatonin.

The brownies, according to the Times, contain just as much melatonin as are found in drug pills but are cheaper and can be purchased with food stamps (another reason for taking a look at the whole question of SNAP benefits?).

Since melatonin is a drug and not an approved food additive, the makers of these products are trying to get around the annoying FDA restrictions by marketing the brownies as “dietary supplements.”  Supplements, by order of Congress when it passed the Dietary Supplement Health and Education Act (DSHEA) of 1994, do not have to meet FDA’s rigorous scientific criteria for safety or efficacy.

DSHEA applied to supplements, not foods, but the FDA has chosen to regulate foods containing such additives by the weaker rules applying to supplements and to deal with them as a regulatory gray area.   Is melatonin a drug, a supplement, or in brownie from a food?  The FDA is going to have to decide this, and fast.

A much longer story in the business section, “Foods with benefits, or so they say” (in which I am quoted) focuses on the entire point of functional foods: the ability to put something in a product that allows you to market it using health and wellness claims.  Health claims sell food products.  People like buying products with a “health aura,” no matter how poorly the health claim is supported by science.  Science is irrelevant here.  Marketing is what’s relevant.

As I discuss in my book, Food Politics, until the early 1990s, the FDA did not allow health claims on food products.  Claiming a specific health benefit for a food, said the FDA, meant that the food was being marketed as a drug.  If a food was being marketed as a drug, it needed to prove safety and efficacy, something no food maker wanted to do.

When Congress passed the Nutrition Labeling and Education Act in 1990, it struck a deal with the food industry.  The industry was objecting that because Nutrition Facts labels required them to say what was bad about their products, they ought to be allowed to say what was good about them.  Congress agreed, and forced the FDA to review the science linking certain food ingredients to health benefits as a basis for permitting health claims.

The FDA approved some claims but rejected others.  The rejected companies took the FDA to court, and the courts mostly ruled in favor of the companies on the grounds of the First Amendment.  The FDA stopped trying to control unsupported health claims and only recently has taken then on again.

But as sales soar, federal regulators worry that some packaged foods that scream healthy on their labels are in fact no healthier than many ordinary brands. Federal Trade Commission officials have been cracking down on products that, in their view, make dubious or exaggerated claims. Overwhelmed regulators concede that they are struggling to police this booming market, despite recent settlements with makers of brands like Kellogg’s Rice Krispies and Dannon’s Activia, which the authorities say oversold their health benefits.

To the distress of international food marketers, the U.S. currently has much looser regulations about health claims than are available in Europe.  The European Food Safety Authority has been reviewing thousands of petitions for health claims on food products and turning most of them down as scientifically unsubstantiated.  That doesn’t stop American food makers from loading on the claims.

From the ivory tower in which I sit, the remedy is easy: don’t allow health claims on processed foods at all.  The claims are all inherently misleading, as would be obvious if you gave it a minute’s thought.

But if they aren’t worth much to you, they are worth plenty to the marketers of processed foods.  And that’s what this is really about.