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Should You Take a Multivitamin?

You may have seen or heard information warning you against taking a daily multivitamin. Even your doctor may have told you not to take them. Most doctors have no training in nutrition and so they may not be aware that vitamins help prevent disease.

You'll also hear a lot of misinformation stating that you can get all of your nutrients from food and so there is no need to take vitamins. I find it interesting that these same sources never bother to warn you about the dangers of hotdogs, colas, and processed foods. They just focus in on vitamins.

Here is the truth about vitamins - most people cannot obtain all of their nutritional requirements from food and should take a multivitamin. This is especially true for those that are eating the mainstream American diet of processed meats, cheese, chips, colas, and fast food.

Even if you eat healthy - you can most likely benefit from taking a multivitamin to be sure you are getting all of your nutritional requirements met.

Research Shows Taking a Multivitamin May Help Prevent Cancer

Research has shown taking a multivitamin may prevent cancer. For example, Guizano et al. (2012) found that men who take a multivitamin had fewer incidences of cancer than those taking a placebo. In case you aren't familiar with the term, a placebo is a "fake" pill often used in research studies so that the participants won't know which group they are in. In this way, the participants wouldn't know if they were getting the real vitamin or the fake vitamin.

The participants in this study were 14,641 male US physicians aged 50 years or older. They were split into two groups - those receiving the multivitamin and those receiving the placebo. The study began in 1997 and ended in 2011. At the end of the study, those participants taking a multivitamin had a statistically significant reduction in the incidence of cancer as compared to the placebo group.

Another study by Enstrom et al. (1992) found that taking vitamin C supplements led to a decreased risk of dying from all causes.

Some studies have found better outcomes for people taking multivitamins, even if they already have cancer. Kwan et al. (2011) found that women with early stage breast cancer had more positive outcomes and less cancer recurrence if they took a multivitamin and also engaged in other health promoting activities, such as exercise, and eating more fruits and vegetables.

It should be noted that not all research studies find a relationship between multivitamin intake and cancer reduction. Although part of this could be due to design flaws in some of the studies - or perhaps vitamins don't work for all cancers. Another confounding issue in vitamin studies is that many of them don't use a high enough dosage of the vitamin to make a real difference. This could be one reason that some research studies show no effect of taking vitamins.

In any case, although not all studies find a reduction of cancers, I think that most research is pretty clear that vitamins can be beneficial to your health. This is especially true if your diet is poor.

Are Vitamins Safe?

Taking a multivitamin as directed on the label is pretty safe, although there are people who sometimes try to tell you otherwise.

You will sometimes be warned that mulitivitamins contain more than the RDA of particular vitamins. This part is actually true, but sometimes this is a good thing. The RDA is the amount of a vitamin needed to prevent disease. It doesn't mean that it is the amount needed for optimal health.

Watch Out for Too Much Vitamin B6

One warning I do want to mention is that it is possible to get too much vitamin B6. Even though it is a water soluble vitamin, complications of too much B6 have been linked to nerve damage and skin lesions. For more info on this topic please visit

Sometimes I think I've found the perfect multivitamin, but then I see that it contains a ridiculous amount of B6 and so I steer clear. For example, I'd never take a multivitamin that contains 50 to 100 mg of B6 when 2 mg of B6 is optimal.

What is the RDA

RDA stands for Recommended Daily Allowance or Recommended Dietary Allowance (depending on who you ask). They both mean essentially the same thing. The RDA is the amount of a vitamin that prevents a particular disease. These were established years ago by taking a small group of healthy people and determining how much of a vitamin prevented a particular disease. Let's use vitamin C as an example. The RDA for vitamin C is only 60 mg. This is the amount of vitamin C that prevents scurvy. However, the RDA in no way implies that 60 mg is the optimal amount of vitamin C.

What people should focus on when choosing a multivitamin, or vitamins in general, is what the optimal dosage is. Unfortunately, this hasn't been determined. There isn't a lot of research conducted to determine the optimal amount of vitamins because there isn't much money in vitamins and so who is going to fund these studies?

You should also focus on the upper tolerable limit of vitamins. It is possible to get too much of a good thing. This is especially true for vitamin A and also for iron. The upper limit for vitamin A is 10,000 IU for adults. Most multivitamins contain 3500 to 5000 IU for vitamin A. What I'm talking about here is preformed vitamin A (usually in the form of vitamin A acetate) and not beta carotene (a vitamin A precursor). Preformed vitamin A is also found in meats, eggs, and dairy, but not in plant-based foods.

Vitamins without Preformed Vitamin A

I prefer vitamins that don't contain preformed vitamin A, but have only beta carotene instead. These aren't too easy to find.

According to the label, Raw One Vitamins contain only beta carotene and not preformed vitamin A.

Other multis usually contain a mix of vitamin A acetate or palmitate and beta carotene. See the table below for a vitamin A to beta carotene ratio comparison for some common brands:

Centrum 3500 IU 29 % as beta carotene
Raw One for Women 5000 IU 100% as beta carotene
GNC Women's Ultra Mega 5000 IU 50% as beta carotene
GNC Mega Man 5000 IU 50% as beta carotene
One a Day Essential 3000 IU 17% as beta carotene
Nature Made Multi Complete 2500 IU 60% as beta carotene
Now Daily Vits 5000 IU 20% as beta carotene
Optimen 10000 IU as natural mixed carotenoids (so I'm assuming no preformed A?)
Optiwomen 5000 IU as beta carotene and vitamin A palmitate - does not specify amounts

So, at least in this sample, only Raw One vitamins are without preformed vitamin A. This is true for both the men's and the women's.

Vitamins without Iron

Vitamins without iron are easy to find. Because too much iron is believed to contribute to heart attacks and heart disease, men's vitamins typically do not contain iron. This is because men are more likely than women to have heart disease and also because men don't lose blood every month like women do when they have their monthly period.

Vitamins designed for those over 50 usually don't contain iron either. The reason for this is because women who are still menstruating need the extra iron because of their monthly period. It is assumed that most women over 50 are done with that (although this isn't always true) and so there is no iron in the over 50 vitamins.

The Difference Between Men's and Women's Vitamins

Many vitamin companies now market their vitamins as specifically for men or for women. Because of the iron present in the women's vitamins, men probably shouldn't take women's vitamins, but I believe in most cases it is okay for women to take men's vitamins.

In fact, I often take the men's vitamins. This may seem strange, but I often alternate the brand of multivitamin I take and I also alternate between the men's and women's multivitamins.

Often, the difference between the men's and women's versions of vitamins have only minor differences.

For example, if you take a look at the label for GNC Mega Men vitamins, the vitamins are almost the same as the Women's Ultra Mega except for a few things. One of these is calcium - they put 500 mg of calcium in the women's vitamin vs 200 mg in the men's. There is also iron in the women's, but not in the men's.

Another difference is that the GNC women's vitamins contain the Beauty Blend:

  • alpha-Lipoic Acid
  • Green Tea Leaves
  • Collagen
  • Hyaluronic Acid (HA)

whereas the men's contains the Amino Acid Blend:

  • L-Carnitine
  • L-Glutamine
  • L-Methionine
  • L-Taurine

The main difference between the men's and women's in GNC's multi is that women are supposed to look pretty and men are supposed to build muscle.

Since I'd like to do both, I alternate the vitamins. I also alternate both of these with the Women's Raw One vitamins. In this way, I am giving my body a little variety instead of consuming the exact same vitamins day after day.

Basically, when choosing the best vitamin for you, read the label, and determine the best vitamin for you and your fitness and health goals.

Food Based Vitamins

Some vitamin companies, such as Garden of Life and Labrada offer food based vitamins. These are typically better than synthetic vitamins because supposedly the vitamins contain the other ingredients present in food that are good for us, and not just an isolated vitamin. However, keep in mind that food-based doesn't necessarily mean "whole food". Food based, such as Raw One vitamins and Labrada's lean body vitamins are probably better than non-food based vitamins, but eating healthy whole foods is always best. The multivitamin is just there to supplement an already healthy diet and is not meant to replace the vitamins obtained from healthy eating.

Recommended Vitamins

Below are my personal favorite multivitamins. And yes, I do get a small commission if you purchase these at Amazon via my site , but these really are my favorites :). They are raw food based vitamins that contain most of the vitamins and minerals that I want, but none of the extra stuff that I don't.


Enstrom JE, Kanim LE, Klein MA (1992). Vitamin C intake and mortality among a sample of the United States population. Epidemiology 3: 194-202.

Gaziano JM, Sesso HD, Christen WG, Bubes V, Smith JP, MacFadyen J, Schvartz M, Manson JE, Glynn RJ, Buring JE.(2012) Multivitamins in the prevention of cancer in men: the Physicians' Health Study II randomized controlled trial. JAMA 308(18): 1871-1880.

Kwan ML, Greenlee H, Lee VS, Castillo A, Gunderson EP, Habel LA, Kushi LH, Sweeney C, Tam EK, Caan BJ.(2011) Multivitamin use and breast cancer outcomes in women with early-stage breast cancer: the Life After Cancer Epidemiology study. Breast Cancer Research and Treatment 130(1): 195-205.