- Cardiovascular disease (CVD)
- Impaired immunity
- Accelerated aging
So, Why Is The U.S. Preventive Services Task Force So Down on Multivitamins?
- The most recent U.S. Preventive Services Task Force (USPSTF) review on the potential benefits of taking a multivitamin (MVI) supplement concluded that due to numerous study design flaws there is not enough evidence to recommend taking a MVI to reduce the risk of chronic diseases and cancer.
- No benefit they tells us? This statement directly conflicts with that fact that in the studies they analyzed the results clearly show that those who took a multivitamin had an 6-31% lower risk of developing cancer (p=0.04) versus those who didn’t. If this data is correct, taking a multivitamin would lead to 9-47 Million fewer cancer diagnoses in U.S. men (these studies did not find a a clear benefit for women who took a multivitamin…we are not sure why but likely has to do with the classic analysis of “garbage in, garbage out”).
- Unfortunately, many in the medical community, the media and the USPSTF are all now telling the public that “Multivitamins should not be used.”
What’s The Problem?
- All studies used MVI’s with various compositions and doses of micronutrients. This leads to an inability to make any generalized statement of efficacy since the doses and compositions of the component micronutrients were wildly different from one multivitamin product to another. We also know that there is pill to pill and batch to batch variability in many lower quality multivitamins, such as those used in some of these studies.
- There was no true ’non-exposed’ group (no control for nutrient intake). This means that even the people not taking a multivitamin were eating food that contains natural amounts of micronutrients or were fortified with extra micronutrients. To clearly show a benefit of taking a MVI the studies would need to be much larger to establish statistical significance since many of the study participants in both arms consumed food that is full of micronutrients.
- Questionnaires (subject to recall bias) were used for assessing intake and MVI compliance instead of testing blood levels to quantify true micronutrient levels. We all know that when we are asked about our use and compliance of taking a pill we tend to write down what we think the doctors want to hear (i.e. “yes, I was compliant and I took the pill.”) After all, who doesn’t want to please their doctor?
- All of these studies were conducted with the use of healthy enrollees. These are folks who have better lifestyle habits than the typical population. This means that even the individuals who didn’t take a MVI tended to consume a reasonably healthy diet…likely comprised of many of the micronutrients in the MVI.
Additionally, it is well known among nutrition experts that the composition and dose levels of the individual micronutrients in the MVI’s used in these studies may in fact be unsafe. For example:
- Many MVI’s contain iron, however most healthy adults do not need supplemental iron (a free radical producing micronutrient). It has been postulated that iron supplementation may increase the risk of CVD and cancer. If this correlation is true, taking a MVI with iron (such as some of those analyzed in the above review) could decrease any potential health benefits that might have been derived from the other micronutrients.
- Many MVI’s contain higher than recommended doses of various micronutrients (i.e. vitamin A is commonly dosed a levels many times greater than the recommended dose.) When taken at these megadose levels, antioxidant micronutrients can act as pro-oxidants (free radicals)…which can cause DNA damage. More of a particular micronutrient is not necessarily a good thing (see the dose response curve below).
- Many MVI’s contain only one isolated form of a particular vitamin. For example, vitamin E has numerous different forms that occur naturally in foods (alpha-, beta-, gamma-, and delta-tocopherols and tocotrienols). The vast majority of MVI’s only contain one subtype, predominately ‘alpha-tocopherol,’ which if not balanced by the other forms can lead to oxidation…DNA damage. Play it safe and pick a MVI that contains “mixed tocopherols.” Additionally, it helps if the MVI actually contains the most active forms of each vitamin (i.e. vitamin D3, K2, etc.)
- I am aware of not a single large scale, multi-year study that has actually checked the levels of more than just a handful of micronutrients (vitamins and minerals) in their subjects before and during the years of supplementation to see if they are deficient in any of these important compounds. After all, each of us absorb micronutrients differently so that one person may absorb very well and others hardly at all. Additionally, elimination and metabolism of these compounds will also vary from person to person. Diet, overall health, age, medication use and many other factors will impact an individual’s micronutrient profile. If you don’t test for these and supplement accordingly you will have little to no impact on a person’s health by simply giving them a ‘one size fits’ all multivitamin. (Hint: ask your doctor if they do micronutrient testing).
- All of these issues—and many others—make analyses of MVI studies confusing at best.
For those of you who want to optimize your micronutrient levels it is essential to know which vitamins and minerals need to be added to your current diet or supplementation regimen. Research shows that 50% of those taking a multivitamin are still deficient in individual micronutrients.
Ask your doctor to order you a micronutrient test.
The one I use evaluates the levels of 33 vitamins, minerals and amino acids as well as provides an assessment of your overall antioxidant level and immune system status. Your report will include a detailed repletion list to guide you on which micronutrients you need to add to your supplementation regimen or diet and gives you recommendations on specific dosages.
Without micronutrient testing you are completely in the dark on your micronutrient status.
The Bottom Line:
- Until researchers are able to address all these study design issues and conduct better experiments we will not have the answers we need to determine the potential health benefits of MVIs…I don’t see this happening anytime soon.
- So, in light of the fact that most of us do not consume diets with the full complement of all of the micronutrients we need to support optimal health, I recommend that you consider taking a high quality MVI using micronutrient dosages that meet the latest recommended daily allowances established by the Food and Nutrition Board of the U.S. Institute of Medicine.
- Think of this recommendation as a “nutrition insurance policy.”
- Before you start taking a MVI, talk with your doctor about whether they feel this is appropriate for you.
- Ask your doctor about micronutrient testing. Without knowing your levels you are in the dark on what micronutrients (and how much) you need to add to your diet or supplementation regimen.
This Are My Favorite Multivitamins For Men & Women:
If you prefer to drink your micronutrients, here’s my favorite. I add this to a glass of unsweetened almond milk. It’s full of plant protein, probiotics, vitamins, minerals and numerous anti-cancer phytonutrients:
Drinking juices and smoothies are another way to drink your micronutrients. Learn more about this here.
- Linus Pauling Institute (Multivitamin/Mineral Supplements)
- Harvard School of Public Health (Vitamins)
- Dr. Mark Hyman (Why You Should Not Stop Taking Your Vitamins)
- Life Over Cancer Blog (Breast Cancer And Multivitamins: A Closer Look)
- WebMD (Making The Most Out Of Multivitamins)
- Life Extension Magazine (Findings From Flawed Study Used To Discredit Multivitamin/Mineral Supplements)
- Dr Geo’s Blog (The Supplement Causing Cancer Story Is BS…)
- 1UpOnCancer.com (Know Your Supplements- by Dr Lawenda)