4. Do Multivitamins Work?

TL;DR: Most multivitamins don’t work, so research for one that does, or make your own custom “stack” from individual supplements as it suits your needs. Plugin your typical diet to a nutrition tracker to see your gaps.

Introduction

So far in our supplementation section, we’ve talked about why supplements are useful, the best muscle building and fat loss supplements, how to avoid shitty supplements, and how to choose the right form of supplement for each nutrient. In this article, we bring some ideas together and outline a system you can use to create your own personal multivitamin stack.

Multivitamins

Multivitamins are the most commonly taken supplement in the developed world, including at least half of the US population [1], and its use has increased rapidly in the last couple decades [2]. Unfortunately, to date, studies as a whole appear to have mixed findings on the benefits of taking multivitamins.

A meta-analysis of randomized control trials from March to October of 2012 included 21 studies with a total of 91,074 people, and 8794 deaths [2]. The average age was 62 and the average duration of supplementation was 43 months. The results? There was no correlation found between taking a multivitamin and reduced mortality. This is not an usual finding, as the same results are reported in other large studies that use multivariate-adjusted analysis [3]

Note: multivariate analysis is adjusting for factors other than multivitamin use (though it can be applied to any factor, not just multivitamins). For example, multivariate analysis would adjust for servings of vegetable consumption in studies that follow a group of people taking multivitamins because those who take a multivitamin may be more likely to eat vegetables. Not adjusting for variables like this is not a fair comparison because you can’t tell if the vegetables are causing the benefits, or if it is the actual multivitamins. Most good studies control for multiple variables, but many do not, and without it, you can only show correlation, not causation.

It is important to note that some studies do find a benefit to multivitamins, for instance this one that followed 31,671 Swedish women over 10.2 years and analyzed results using multivariate analysis. It showed the multivitamin group had 73% the chance of dying as the non-multivitamin group [4]. This study notes, however, that more long term studies are needed to confirm this finding.

This same study noted that the typical contents in these multivitamins are:

Vitamin A (0.9 mg)
Vitamin C (60 mg)
Vitamin D (5 μg)
Vitamin E (9 mg)
Thiamine (1.2 mg)
Riboflavin (1.4 mg)
Vitamin B-6 (1.8 mg)
Vitamin B-12 (3 μg)
Folic acid (400 μg)

This list will be used as a reference below.

The Advantage of Individual Supplements

It is more difficult to find clear studies on individual supplements compared to a multivitamin, but from the current studies, it appears that individual supplements are more effective than pre-formulated multivitamins. For this reason, for those who really want to achieve peak performance, it is worth doing some work up front to make your own multivitamin composed of individual nutrients you select for your unique needs.

From one meta-study looking at randomized control trials of vitamin d supplementation, for example, there was a statistically significant, moderate reduction in mortality [5]. There are also tens of thousands of studies with clear evidence that low vitamin d levels in the blood increase mortality, often very significantly [6][5]. Since taking vitamin d raises blood levels of vitamin d [7], it would be reasonable to make the connection that supplementing vitamin d would reduce mortality.

Other individual nutrients that you might find in a multivitamin show promise as well, and yet multivitamins themselves don’t, but why might that be? In all honesty, there isn’t scientific consensus yet on how and why some supplements seem to work and others don’t, but the following reasons are good starting places.

Reasons why multivitamins may be ineffective

The multivitamin studies mentioned earlier show unclear, if any, benefits, but individual supplements do show benefits. Why? It boils down to the fact that most multivitamins are not very good.

Here are at least 5 reasons:

Form: Some forms of vitamins are more bioavailable than others. Folic acid is one form to get folate from, but you can also supplement directly with folate, which is much easier for your body to use and is more bioavailable. As seen in the list above, multivitamins unfortunately often use folic acid, which is less effective. See more in our article on choosing the right form of supplements.
Amount: Often, multivitamins skimp on how much they put in. For instance, the typical amounts listed above show a vitamin D dosage of 5 μg (200 IU). Considering the fact that our ancestors evolved with a typical daily intake of 10,000 IU [6], the amount in multivitamins is too low to have a strong enough effect. Especially considering the fact that vitamin D deficiency is very rare, and you can likely take up to 10,000 IU per day safely, there is no good reason it is not included in higher amounts in multivitamins [8].
Combinations: The way vitamins interact with each other can be complicated. Sometimes, it is the ratio of one vitamin to another that is most important, not the amount of one or the amount of the other by itself. For instance, zinc and copper should have a ratio of about 8:1, omega-3 to omega-6 should be taken in a ratio of about 1:1, and vitamin d and vitamin k should be taken in a certain ratio with each other as well. Often, this is not adequately considered in multivitamin formulations. For instance, there is vitamin d in the listed amounts above, but no vitamin k.
Individuality: Different people need different supplements because they eat different foods, have different activity levels and unique metabolisms and live in different areas. One glaring example of this is vitamin d, which you can make in your skin when the sun hits it. Those who live in areas with less sun will have lower blood levels of vitamin d. Multivitamins are usually not flexible enough to address these needs.
Some nutrients should not be taken as supplements yet: for example, some multivitamins contain calcium, which in many studies has shown increased risk of heart disease and heart attack. For whatever reason, calcium intake through diet has no increase in heart attack risk, perhaps due to combinations with other nutrients in the food. [9]

To be clear, there may be some good multivitamin formulations out there, but they are not usually mainstream. If you want to get the benefits of a multivitamin without formulating one yourself, do some research and find a good multivitamin that doesn’t have the above downfalls. If you want to really optimize your nutrient intake and are willing to invest the effort, see the below strategy to formulate your own multivitamin.

What To Do Instead

Identify goals

You should always know why you take a supplement before doing so. Some people waste large amounts of time and money researching and buying supplements they may not need. Determine a goal like having more energy, more mental clarity, to live longer, or just as a general health improvement.

If possible, have a way to measure your goal over time to see if your multivitamin stack is actually working. This could be as simple as recording your energy levels each day and tracking this over time, or as detailed as getting a blood test for certain nutrition levels before and after supplementing.

Some supplements are expensive, so consider setting a monthly budget for your custom multivitamin.

Keep a food log for a week

Everyone eats different foods, so everyone will have different deficiencies in their diet, unless they eat a perfect diet. This means everyone should tailor their supplements to their own diet. To do this, use a food tracker like MyFitnessPal, which also has an app for mobile devices. At the end of each day, you should be able to see your intake of each nutrient as a % of the recommended daily intake (RDI).

Track your nutrient intake over a week, and look to see what your deficiencies are.

See the example below for one day:

Foods eaten (add these to your tracker with the amount you ate):

Nutrition from these foods (automatically calculated):

Once you have all 7 days recorded, move on to step 3.

Identify supplements to take

After you have your food log for one week, look at which deficiencies are common across the week. To really get specific, you can get a calculator out and average your intake of each nutrient over the week by adding all 7 days and dividing by 7. Putting this in a spreadsheet by exporting your data from the nutrition tracker may be helpful here.

Looking at the example above, you can see the following headings: general, carbohydrates, lipids, protein, vitamins and minerals. For the purposes of this article, ignore general (calories, alcohol, caffeine, and water), carbohydrates, and lipids and just focus on protein, nutrients and minerals. For all three, check your RDI using our list of all nutrients. Then, compare your current intake for each nutrient with your RDI, and write down this difference. For example, above, only 57.8 micrograms of Vitamin K is consumed each day, and the RDI for males for example is 120 micrograms. This means that you should look for a supplement that is roughly 60 micrograms per serving. If the supplement is more than this, you can take it every other day or every third day, and if it is less than this dose, you can take two or more servings per day.

As you can see from the example again, the major deficiencies include Vitamin D (only 12%), Vitamin E, Vitamin K, Calcium, Magnesium, and Potassium. If there are too many deficiencies that it becomes overwhelming, just start with your biggest deficiency first and try filling that. It’s better to add supplements in slowly rather than all at once.

Note: before supplementing, ask yourself if you could get this nutrient from a food instead, which is usually better for you. See our list of all nutrients to find a food source for each nutrient.

Research supplements

For each supplement you want to take, the most important things to look for are ingredients, a trusted brand, the form of the nutrient, and for most people, the price. You can also check out our list of trusted brands for supplementing here.

Ingredients: Ideally, a supplement contains only the actual nutrient you are looking for with no fillers. Some brands even say “pure xyz” or “100% xyz”. If there are harmless preservatives in small amounts, or if there are ingredients used to make the capsule, that’s no big deal, but if there are multiple ingredients that aren’t necessary, that can be a red flag. Ultimately, it comes down to trust since it can be difficult to tell which ingredients are necessary and which aren’t, which leads us to finding a trusted brand.

Trusted Brand: Since supplements are unregulated, it is important to choose a well trusted brand and if possible, one that is 3rd party tested. If you can find studies on the supplement, that would be ideal, but that is rare. One helpful way to find trustworthy brands anecdotally is to look at reviews on Amazon and other websites like www.iherb.com. Usually, customers who have actually tried the product are most trustworthy sources of information. Ask your friends if they have any experience with the supplements you want to try, and look on forums like Reddit. Ultimately, you may have to try out a couple different brands and see how you feel about them.

Form: For each nutrient you want to take, first check our article on the right form of supplements so that you choose the best form that is most bioavailable. As noted in that article, for some nutrients, you should not take a supplement and you should only get that nutrient from real foods, so make sure to check this list before purchasing.

Cost: A helpful tip to keep track of cost is to list supplements in $/month. This is helpful to standardize cost across different brands. For instance, if a supplement costs $30, and has 120 pills, and you need to take 2 per day, it will cost you roughly $15 per month. Buy bulk powder versions of a supplement if possible because they are usually much cheaper and more pure.

Buy

Take the deficiencies you chose to address, and the brands you chose to address them with. Tally the total cost/month, and check that it is in line with your budget. Once you’ve decided on what to purchase, move on to step 6.

Implement

Many people make it this far with their supplement routine, but then they don’t stick to the habit of taking the supplement each day that they spent all of that time researching. Have a set schedule for taking these supplements at the same time each day to form the habit. See more on building habits here. Note the time of day to take supplements and whether to take with food or not.

Follow-Up

Before you begin taking your new supplement stack, note your goal from step 1, and see if these supplements are helping you to reach that goal. For instance, record your energy levels out of 10 each day, then start taking your supplement for at least two weeks after that and continue to record your energy levels. Look back after and see if you are making any progress. If you aren’t, then you may need to try a different supplement.

It’s always good to keep in mind that you should move at your own pace and be patient. Consider only adding one nutrient at a time over a longer period to see the individual effects. A methodical approach of tracking and measuring your goals, finding the best brands, and monitoring your monthly costs will set you up for success long term.

Conclusion

Many people use supplements to fill gaps in their diet that are too difficult to fill using food day to day. The most popular choice is a multivitamin, but research doesn’t seem to show strong benefits, for several possible reasons. Since supplements for individual nutrients like Vitamin D do appear to work, you can take many individual supplements together targeted to your unique needs. To do this, record your food intake over a week and see what nutrients you are missing. Then, find the best supplement in terms of ingredients, brand, form, and cost. Try out your new supplements and track any improvements you notice over time.