Which prenatal vitamin is best?

Vitamin supplementation is unnecessary for the vast majority of people. You wouldn’t know this walking through a drug store, where you’ll usually find an entire aisle packed with supplements. Alternative health providers like naturopaths tend to be strong supporters of supplementation, but this advice seems to be based mainly on the belief that “vitamins are magic” rather than good science. The best research hasn’t established a strong evidence base for taking supplements. We definitely need vitamins in our diet to live. But that’s where we should be getting those vitamins – from our food, instead of from pills. If you eat a reasonable and balanced diet, and have no medical conditions that require special consideration, vitamin supplementation won’t offer meaningful health benefits. In the absence of any deficiency, vitamin supplements seem to be useless at best and harmful at worst.

Do vitamins reduce the risk of cancer or heart disease?

It is a triumph of marketing over evidence that millions take supplements every day. There is no question we need vitamins in our diet to live. But do we need vitamin supplements? It’s not so clear. There is evidence that our diets, even in developed countries, can be deficient in some micronutrients. But there’s also a lack of evidence to demonstrate that routine supplementation is beneficial. And there’s no convincing evidence that supplementing vitamins in the absence of deficiency is beneficial. Studies of supplements suggest that most vitamins are useless at best and harmful at worst. Yet the sales of vitamins seem completely immune to negative publicity. One negative clinical trial can kill a drug, but vitamins retain an aura of wellness, even as the evidence accumulates that they may not offer any meaningful health benefits. So why do so many buy supplements? As I’ve said before, vitamins are magic. Or more accurately, we believe this to be the case.

There can be many reasons for taking vitamins but one of the most popular I hear is “insurance” which is effectively primary prevention – taking a supplement in the absence of a confirmed deficiency or medical need with the belief we’re better off for taking it. A survey backs this up – 48% reported “to improve overall health” as the primary reason for taking vitamins. Yes, there is some vitamin and supplement use that is appropriate and science-based: Vitamin D deficiencies can occur, particularly in northern climates. Folic acid supplements during pregnancy can reduce the risk of neural tube defects. Vitamin B12 supplementation is often justified in the elderly. But what about in the absence of any clear medical need?

The facts about alternative medicine

People have been living on earth for about 250,000 years. For the past 5,000 healers have been trying to heal the sick. For all but the past 200, they haven’t been very good at it.

– Dr. Paul Offit

Twenty years is a long time in medicine. I celebrated my 20th pharmacy class reunion last weekend. Of course reunions are time to reflect back to our early years as pharmacists. Lots has changed. Much of the therapeutics I was taught is now obsolete. In 1993, HIV was a death sentence and there were only three, largely ineffective drugs available. Thanks to new drugs, HIV can now be managed like a chronic disease, and some of my colleagues have HIV-focused pharmacy practices. The same dramatic changes have occurred in fields like cancer, and transplant medicine. And in some cases, the cause of disease has become more clear – my old textbooks make no mention of Helicobacter pylori as a cause of ulcers.

The practice of pharmacy has changed, too. On the positive side, pharmacists are working in new settings where they can focus on medication management, and not just dispensing prescriptions. Regulators are granting pharmacists the ability to take on new roles, and pharmacists are being compensated for more than simply “count, pour, lick and stick.” From that perspective, it’s a promising time to be a pharmacist. But there’s a much more disturbing side to the profession that’s emerging, too. Community (retail) pharmacy practice is under pricing and competitive pressure, and smaller pharmacies are being subsumed into big retailers where the pharmacy department is buried in the back – a loss leader to bring in patients, but hardly with a health-care focus. And most disturbingly, I see a move within retail pharmacy practice to leverage its professional credibility to sell all types of modern-day snake oil, ranging from detox kits and “cleanses” to dubious “food intolerance” testing. Homeopathic remedies (an elaborate placebo system of sugar pills) are increasingly found on pharmacy shelves, alongside real medicine. And don’t forget the enormous wall of vitamins that seems to get larger and larger. Yes, complementary and alternative medicine is booming, and pharmacy wants its share. Pharmacy regulators turn a blind eye. What do my pharmacy colleagues tell me? They’ll tell me it’s customer demand, and that they don’t recommend the quackery. To me, I see this trend as damaging the credibility of pharmacists in the eyes of the public and of other health professionals.

Weekend Reading

Anti-scientific, Anti-GMO Propaganda

Summer feels like it’s finally here in Canada (well, Toronto at least). Here’s what I’ve been reading.

Intravenous vitamin injections: Where’s the evidence?

Vitamins are magic. Especially when they’re injected. Roll up the sleeve, find a vein, insert a needle and watch that colourful concoction flow directly into the bloodstream. It may sound somewhat illicit, but that person infusing it is wearing a white coat, and you’re sitting in a chic clinic. There must be something to it, right? Intravenous vitamin injections are popular with celebrities and have even been described by Dr. Oz as “cutting edge”. Advocates claim vitamin injections can benefit serious conditions like cancer, Parkinson’s disease, macular degeneration, fibromyalgia, depression, and that modern-day obsession, “detoxification”. And vitamin infusions aren’t just for the ill. They’re also touted as helpful for preventing illness, too. A search for vitamin injections brings up millions of hits and dozens of advertisements. There is no question that vitamin injections are popular. But despite all the hype and all the endorsements, there is no credible evidence to suggest that routine vitamin infusions are necessary or offer any meaningful health benefit. Vitamin infusions are a marketing creation, giving the illusion you’re doing something for your health, but lacking any demonstrable efficacy. What’s more concerning, providers of vitamin therapies target their marketing at those fighting life-threatening illnesses like cancer, selling unproven treatments in the absence of good scientific evidence that they are beneficial.

The intravenous vitamin industry is a sideshow to science-based health care. Yes, there is an established medical role for injectable vitamins, though it’s no energy-boosting cure-all – they’re used to replace what we should obtain in our diet. As a hospital-based pharmacist I used to prepare sterile bags of total parenteral nutrition (TPN), a mixture of vitamins, carbohydrate, protein and fat that completely replaced the requirement to eat. TPN is effective, but not without risks, and far less preferable than getting your nutrients the old fashioned way – by eating them. There’s also the routine use of injectable vitamins like B12, or iron, all of which can be science-based when used to address true deficiencies, or to manage specific drug toxicities. IV vitamins (particularly thiamine) are also used in the emergency room, given to alcohol-dependent patients in order to prevent Wernicke’s encephalopathy. And there is the therapeutic use of high-dose minerals like intravenous magnesium for acute asthma attacks. But there is no medical justification to infuse vitamins into a vein when you can more appropriately obtain those nutrients in your diet.

What’s really in your supplement?

When you pick up a bottle of supplements, should you trust what the label says? While there is the perception that supplements are effective and inherently safe, there are good reasons to be skeptical. Few supplements are backed by good evidence that show they work as claimed. The risks of supplements are often not well understood. And importantly, the entire process of manufacturing, distributing, and marketing supplements is subject to a different set of rules than for drugs. These products may sit on pharmacy shelves, side-by-side with bottles of Tylenol, but they are held to significantly lower safety and efficacy standards. So while the number of products for sale has grown dramatically, so has the challenge to identify supplements that are truly safe and effective.

There’s little evidence supplements are beneficial. So why do we take them?

It may or may not surprise you that I take few nutritional supplements. Apart from sporadic vitamin D in winter, I don’t take any vitamins or supplements routinely, nor do I give any to my children. Why? There is little to no evidence suggesting that dietary deficiencies are widespread, nor is there good evidence to suggest that vitamin supplements are beneficial in the absence of deficiency. I don’t have any need for an other supplements, nor am I confident in the scientific evidence for many of them. This position of “no supplements” is a cautious and conservative one, but is based on a consideration of the scientific evidence. I view decisions about healthcare as evaluations of risk and benefit, and then cost if necessary. Given supplementation (with some exceptions) has no demonstrable benefits and, in some cases, a little risk, the odds favour not supplementing in most cases. Add in costs, and it’s even less attractive as a routine health strategy.

Yet a decision not to take vitamins or supplements regularly, particularly in the absence of a medical need, is becoming a minority position. Supplement use has grown over the past 40 years among Americans, with the National Health and Nutrition Examination Survey (NHANES) showing steadily increasing utilization among younger and older adults:

Antioxidants and Exercise: More Harm Than Good?

Multivitamin supplementation has been getting a rough ride in the literature, as evidence emerges that routine supplementation for most is, at best, unnecessary. Some individual vitamins are earning their own unattractive risk/benefit profiles: Products like folic acid, calcium, and beta-carotene all seem inadvisable for routine supplementation in the absence of deficiency or medical indication. Vitamin E, already on the watch list, looks increasingly problematic, with data recently published confirming the suspected association of supplementation with an elevated risk of prostate cancer.

When it comes to health decisions about vitamin supplements, history teaches us a valuable lesson: The danger of assuming therapeutic benefits in the absence of confirmatory evidence. Vitamin supplement have the patina of safety and of health, a feature that’s reinforced when you purchase them: You don’t need a prescription, you don’t get counseled on their use, and there isn’t a long list of frightening potential side effects to accompany the product. You can pull a bottle off the shelf, and take any dose you want. After all, how harmful can vitamins be when you can buy 5 pounds of vitamin C at a time, or vitamin E capsules in a 1000-pack? But the research signals seem to be getting stronger, and most are pointing in the same direction: what we though we knew about antioxidants was based on simplistic hypotheses about nutrition and health. And while we thought we were doing ourselves good with antioxidant supplements, we may have been doing harm.

The benefits and risks of folic acid supplementation

Could a vitamin with proven benefits in one group cause harm to another? That’s the growing concern with folic acid, the vitamin that dramatically reduces the risk of neural tube birth defects such a spina bifida. Studies designed to explore the possible benefits of folic acid for heart disease, stroke and cancer are giving out some worrying signs: At best, folic acid is ineffective, and at worst it may be increasing the risks of some cancers. So what does this say about routine supplementation for the typical healthy individual, and its overall risk and benefit?

This Friday, Your questions about vitamins answered live

This Friday, June 11, I’ll be appearing on the Skeptically Speaking radio show, answering your questions about vitamins. Call in, listen online, or submit your questions in advance. I promise an interesting discussion.