I was flicking through good old Facebook, the book of face, the other day when I came across an advert for yet another multivitamin product under the name of VITL. Presumably a play on the word vital…as in, you vitally need this supplement to be healthy. Or do you?
Multivitamin supplements and other products that fall into that sort of category such as anti-oxidant pills are consumed in huge quantities in the UK and US. Many people swear by them and start their day swallowing down a random amount of varied vitamins. Vitamins are good right? They are important in loads of physiological processes so surely more of them is better?
In reality the science suggests two things rather clearly if you are an average person:
- All your vitamin needs are met by your diet if its fairly balanced
- Taking too much of a particular vitamin can have serious repercussions to your health
I don’t wish to target VITL directly as many companies are peddling their vitamin wares. It’s not the product itself I have an issue with but the target market. It makes medical sense to supplement a vitamin that you are clinically deficient in but trying to sell expensive vitamins to people who don’t need them is a complete waste of the customers money and in some cases potentially harmful to their health.
What is a ‘vitamin’
A vitamin can be defined as such :
‘A vitamin is an organic compound and a vital nutrient that an organism requires in limited amounts’ (the key phrase here is ‘in limited amounts’)
Technically speaking, ‘vitamin’ refers to a chemical compound that an organism requires but cannot synthesise by itself in sufficient quantities. The vitamin must therefore largely be obtained from dietary sources.
Vitamins are classed based on their biological and chemical activity, not on their structure. Therefore a number of vitamin-like compounds (vitamers) may be grouped together under one umbrella vitamin name. For example ‘Vitamin B’ includes a large number of ‘vitamers’ each with their own B number and additional name. Vitamin B9 for example is Folic Acid. Not all vitamers are in the biologically active state but can be converted into this form in the body.
Thirteen vitamins are currently recognised: Vitamins A, B (8 vitamers), C, D, E and K
Vitamins play a varied and diverse role in the body and have widely different functions.
I’ve made a table to summarise this section in brief as it’s fairly in depth!
The large group of vitamin B type-compounds act as co-enzymes (and precursors) in metabolic processes. Co-enzymes are non protein compounds that are required by the protein enzyme to catalyse specific reactions in a cell (1). They therefore perform an extremely important role in the minute by minute function of cells. Acting as co-enzymes is their most recognised functional role but there are many others (2). Large amounts of research effort has been put into uncovering the therapeutic potential of the B vitamin family of compounds. Many do have true therapeutic value but only in the treatment of serve disorders. B9 for example, also known as folic acid, has been shown to reduce the rate of neural tube defects (NTDs) in infants and as a result can be found fortified into many different foods in a hope to reduce the incidence of NTDs in the population (3). There is also some evidence that folic acid supplementation may confer a small reduction in the risk of stroke and cardiovascular disease if taken over a long period of time (4)
Vitamin D possesses hormone-like functions and act as regulators of mineral metabolism and plays a part in the control of tissue growth and differentiation (5). A chronic lack of vitamin D famously leads to ‘rickets’, a disorder of bone growth and structure. Sunlight (certain wavelengths) modify Vitamin D into its active form which is why at least some exposure to the sun is important. Foods are often fortified with vitamin D in countries that receive lower levels of sunlight (less hours and or/less intensity) but can be found naturally in oily fish and eggs (6).
Vitamin C acts as both an enzymatic co-factor and also functions as an anti-oxidants to protect agasint oxidative stress. The vitamin is a co-factor in a number of important enzymatic reactions, a few of which are related to the synthesis of collagen, a key structural protein. A lack of vitamin C can impact collagen production leading to scurvy.
Vitamin C is a well studied vitamin and makes common appearances in health food shops and websites as a sort of ‘cure-all’ especially targeting things like the common cold and other respiratory pathologies (that website link claims you can cure pretty much any disease). However vitamin C supplementation studies have shown conflicting results. A number of studies suggest that vitamin C supplementation may reduce the duration of common colds (7) but it doesn’t seem to prevent colds in the first place (8). The potential protective effects of vitamin C supplements regarding cardiovascular health and lung cancer has also been explored in depth but overall studies suggest no detectable protective effect (9,10,11). Two of these references are systematic reviews and analyse the data from multiple studies. One of which is a Cochrane review who are known to be very thorough in their approach.
Vitamin E has a number of roles including acting as a fat-soluble anti-oxidant. The vitamin essentially mops up free radicals preventing oxidation stress and tissue damage. This vitamin has also been the subject of a study looking at protective effects against major cardiovascular events in middle aged men but supplementation does not increase protection (12) Surprisingly one report suggested vitamin E supplementation might even increase the risk of lung cancer for already at-risk individuals.(13)
Vitamin K is required for the complete synthesis of a number of important proteins involved in blood coagulation (various coagulation factors) , vascular biology and bone metabolism (14). In somewhat of a developing theme, vitamin K supplementation was explored as a means to prevent or reduce the incidence of cardiovascular disease. This makes sense as vitamin K deficiency is associated with the stiffening of arteries (15). Despite this, there is no good evidence that vitamin K supplementation will stop cardiac events occurring in the first place (16). The science also refutes fairy common claims that vitamin K supplements can slow cancerous tumour growth (17).
Overall, studies which look at standard supplementation (rather than the effects of over-supplementation) have produced few promising results. Unless you are deficient in a particular vitamin then supplementation has no detectable benefit to your health. The only possible exception to this is vitamin C supplementation in regards to common cold duration. Additionally, vitamin C supplementation may help in the prevention of common colds when individuals are exercising rigorously in cold environments (18, 19). This seems like a super specific scenario but if you plan on skiing naked for a prolonged period of time than maybe pop a vitamin C tab or two (but not three…that’s just getting silly)
Daily multivitamins are potentially harmful
I’m going to take aim at Berocca here as an example. Berocca is an effervescing tablet that you plop into a glass of water and it releases all it’s tasty, healthy vitamins and minerals (we know the truth berocca you scum bag!). Now, unlike VITL, who I assume have done their research on vitamin absorption, the people behind Berocca have added a ludicrously large % of your RDA (Recommended Daily Allowance) for many of the vitamins. I mean, 1071% of your recommended daily allowance of B1! That is mental for a number of reasons.
A quick excerpt from the brilliant website quackwatch.org about RDAs:
”The RDAs have been published by the National Research Council approximately every five years since 1943. They are defined as “the levels of intake of essential nutrients that, on the basis of scientific knowledge, are judged by the Food and Nutrition Board to be adequate to meet the known nutrient needs of practically all healthy persons.” Neither the RDAs nor the Daily Values listed on food labels are “minimums” or “requirements.” They are deliberately set higher than most people need. The reason quacks say that the RDAs are too low is obvious: if you believe you need more than can be obtained from food, you are more likely to buy supplements”
Firstly I have already shown you that for the average healthy person, supplementing with any vitamin doesn’t provide protection against diseases or make you ‘healthier’ in general.
Secondly, vitamins are only required in limited quantity. The phrase ‘more is better’ is almost always wrong when applied to biology. Any additional vitamins taken in are excreted as waste so those doses are needlessly high.
Finally, those super high percentages may hide a sinister detail. Not only are excess vitamins pointless they have also been linked to increased risk of a variety of diseases. Over-dosing on some of the vitamins can also induce a specific set of symptoms depending on the vitamin as summarised below.
Major studies looking into the effects of long term vitamin supplementation have produced surprising but solid data.
General Mutlivitamin Tablets: Two large meta-studies, headed by the same researchers, that had access to data from hundreds of thousands of people (more likely to show a true effect) found that individuals taking daily multivitamins had an INCREASED RISK OF MORTALITY in comparison to people who don’t (20,21). Mortality of course covers death from all causes so those people taking multivitamins daily have an increased risk of dying in general. That’s pretty bleak. Other studies have looked at certain vitamins in particular and their effects on the incidence rates of specific diseases. The situation is no less bleak unfortunately…
Vitamin A: As the table further up the article shows, vitamin A can be found in green leafy veg, oranges and milk to name just a few sources. Carrots are also a great source. You only need to eat half a carrot to obtain you recommended daily allowance. Now these studies are specific to smokers but beta-carotene (form of vitamin A) was explored for it’s therapeutic value in lung cancer development. Shockingly those smokers on beta carotene supplements saw a 28% increased incidence of lung cancer (which is already comparatively high in smokers), a huge increase! So unexpected was this result that the trial was terminated ahead of schedule. (22, 23)
Vitamin E: A large number of studies have been conducted concerning Vitamin E supplementation and, like vitamin A, the results are rather disturbing. A study trying to determine if vitamin E could be used to reduce cancer and cardiovascular disease uncovered an increased risk of heart failure in patients taking ‘excessive amounts’ of vitamin E (this why those crazy high % RDAs in some products are dangerous!). These patients all had existing vascular disease or diabetes mellitus (24). Perhaps excessive vitamin E exacerbates circulatory problems that surface with both vascular disease and chronic diabetes.
Another study produced a similar finding to the Vitamin A meta-studies in that vitamin E supplementation correlated with increased mortality (25). This was a large study involving over 100,000 individuals. The conclusion says it all:
”High-dosage (> or =400 IU/d) vitamin E supplements may increase all-cause mortality and should be avoided.”
Of relevance to men, a more recent 2011 study with 35,000 participants showed that vitamin E supplementation significantly increased the risk of prostate cancer (26)
Ultimately, the science refutes the phrase ‘you can’t have too much of a good thing’. Multivitamins and specific vitamin supplements have been linked with an increased risk of death in general, prostate cancer in men, skin cancer in women and heart failure in those already at risk.
Admittedly, these trials expose participants to vitamin levels far above their recommended allowance but that shows us how potentially dangerous it is for companies to make products (for daily consumption) with 5 or 10 times the recommended levels.
Summary: Do you need daily multivitamin supplements?
For the average person, the simple answer is a resounding no. All your vitamin needs are met by your diet.
In fact, it should be an aggressive ‘no’ because you may in fact actually be damaging your health. If you do still wish to take daily vitamins then for the love of god at least check the % RDA on the back and stay away from those products that provide 1000% of your RDA in one daily serving.
Whats important to remember is that although the evidence shows that vitamin supplements, in general, will not make you ‘healthier’ this is all assuming you have a fairly balanced life style and diet to begin with. If you are known to have a deficiency in a particular vitamin then supplementing may still be helpful as long as you stay within recommended daily intakes. Of course, listen to your doctor.
Finally, as an added note: I’ve written this article without touching on fitness or training at all. Not many studies focus on this topic and it would be a very short article if I did. The story is much the same as has been told above. Unless you have a legitimate reason to take vitamins, taking extra won’t effect your general health or really impact your training in any meaningful way. Vitamins are peddled all over fitness and body-building websites just like at health food equivalents but now you know that they are a TOTAL WASTE OF MONEY.
My only advice, and this applies to all supplements, is that actual food should always come first. That’s the whole idea of a supplement, to supplement what you are are (or are not) getting through your diet. Your money would be much better spent on frequent purchases of fruit and vegetables.
Any questions? Feel free to reach me at firstname.lastname@example.org
Thanks for reading,
I recommend using Google Scholar to quickly find these studies in full detail.
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