First thing’s first. Most people do not need to take multivitamins. Sadly though people are stupid and tend to self-medicate with them anyway. So let’s start by considering who would need to take a multivitamin: the main groups of people who would need multivitamins are: People on restrictive diets (including people with eating disorders, people on low-kilojoule weight-loss diets, or people fasting), alcoholics, and perhaps the elderly. Do not take this as an invitation to self-medicate, if one of these three categories describes you then you should see a nutritionist or a dietician for dietary advice.

So what would happen if you need to take a multivitamin? Well as a starting point you’d need to know how much of the nutrients you need to get from a supplement, and how much you can get from your diet. In an ideal world a multivitamin+mineral supplement would contain 100% of all nutrients, and would be delivered across 5 or more tablets so that a person who needs say 20% of their nutrients from a multivitamin could take 1/5th the dosage easily.

Sadly though this is not the case. Almost all multivitamins contain way too much of the cheap water soluble B-group vitamins, way too much vitamin C, and low amounts of poor quality nutrients (cheap ingredients with low bioavailability) for everything else. Below I have made a table showing the Australian NRVs (Nutrient Reference Values) for men and women. I based it on the 31-50 age group, but most values are correct 19 through to 70 years. It shows these popular brands available at Woolies and Coles: Cenovis, Berocca Performance, Centrum Advance, and Swisse. I have also included the Life Extension Mix tables, which despite being much more expensive than supermarket brands is far worse.

Abbreviations: RDI – Recommended Daily Intake, AI – Adequate Intake (/day), UL – Upper Level of Intake, NP – Not possible to set, mg – milligram, µg – microgram.

Breakdown

Well there are quite a few areas for concern here, and this is simply going by the state nutrient levels – some lab analyses have shown that nutrient levels are often misreported on the product labels. You will notice the Upper Level of Intake for Magnesium is actually lower than the RDI for men (which is why I’ve highlighted it). The Upper Level is actually specifically in reference to supplement use, as opposed to Magnesium found in food. Life Extension Mix is actually the worst multivitamin in my table here, for the fact that three nutrients contain well above the Upper Level of Intake (Niacin, B6, and Magnesium), as well as containing excessive amounts of Beta-carotene, Thiamin, Riboflavin, Pantothenic acid, B6, Botin, B12, Vitamin C, Vitamin D, and Zinc. This is particularly concerning, much more than the nutrients with low amounts. It contains one hundred times the recommended daily amount of Pantothenic acid, and also one hundred times the recommended daily amount of Biotin. The level of Vitamin C was also of particular concern.

Berocca Performance was the worst of the four supermarket brands I looked at. I chose it because it’s heavily advertised on TV. The first thing to note is that it misses a lot of key nutrients. Like most multivitamins, it is packed with the cheap and readily available shit that the company can pack into their tablet without spending money on balancing it out with the more expensive nutrients. Just about everything it contains it contains in excess of, with the exceptions of Magnesium and Folate. On the plus side, it doesn’t contain any Iron or Copper which are two metals worth leaving out of a multivitamin. Most concerning of all is that it contains above the upper level of intake for Niacin.

Swisse is only slightly better, but their nutrient compositions all over the place. Despite women needing less micro-nutrients than men (except for Iron, obviously), their Women’s formula contains more micro-nutrients for most nutrients. Like Berocca, it contains Niacin in amounts either close to the UL or in excess of it. In addition to containing excessive amounts of B-group vitamins, it contains low levels of Vitamin D, calcium, iodine, and anything else people might actually need, as well as an excessively high level of beta-carotene. At least it’s not Retinol.

Cenovis has just 1% of RDI of Calcium. I’m not sold on whether this multivitamin is better or worse than Swisse, but they’re both bad. Cenovis at least did not contain above the upper level of intake for any nutrients, but like Berocca and Swisse it is missing quite a few key nutrients. On the plus side, it contains decent amounts of Vitamin D and iodine.

Centrim Advance was by far the best of the four brands I looked at. Do keep in mind though that it’s still badly formulated. On the positives: it contains both Retinol and beta-carotene, it contains good levels of Vitamin D3 and Iodine, the b-group vitamins are all above the RDI but not to the excesses of the other brands, and at least it includes Vitamin K. On the negatives, it contains both Iron and Copper, and only half the minerals are at decent levels with the rest at worryingly low or absent levels. This is especially so for calcium with Centrum choosing to use (no surprise) a dirt-cheap form of calcium with poor bioavailability. Look it appears to be somewhat more workable than the others I have looked at, but it still would not be an ideal choice for someone that needs the use of a multivitamin.

Further considerations

Just because a vitamin or mineral doesn’t have a UL does not mean it is safe to over-consume in supplement form. There is no UL for Vitamin C, but NHMRC notes that 1,000mg is a “prudent limit”. They all contain high levels of Folic Acid, which could also be a concern noting that all non-organic wheat-flour used for bread making is fortified with Folic Acid to reduce the risk of Neural Tube Defects at childbirth. Too much Folate in the diet can mask B12 deficiency, as well as make it worse. I did mention earlier that in an ideal world multivitamins would contain everything and be able to be taken in an easily measured dose – that is simply not the case for these products. Yes you could take half a tablet every two days to reduce the dosage by 1/4, however a well formulated option should come pre-packed to be taken at the required dose, and not require consumers to make extra effort to control their dosage.

I’m not sure a “good” multivitamin even exists. As I mentioned above, it would seem that a nutritionist would have to work with the “best available” options rather than an ideal option. Even then they have no guarantees that the tablets can be properly absorb anyway, or that the stated dosage is indeed correct. My advice would be to strongly distrust anything that is actively advertised anyway, and of what’s remaining to be very sceptical and to ask the advice of a professional before selecting a product.