Many of us are deficient in a number of vitamins and minerals, for example, a New Zealand study found that around 50%* of us are deficient in vitamin D and that deficiencies can be detrimental to our health. These deficiencies could be identified and addressed by regularly testing our blood for all these vitamins and minerals and taking supplements of those we are deficient in, but this is time-consuming and expensive. A simple, cheap alternative is to take a multivitamin and this will likely correct any deficiencies. Many or even most of the components may not be needed but these will simply be excreted.
Specific groups of people are even more likely to benefit from taking a multivitamin. These groups include people with diet limitations due to allergies and strict vegetarians who eat no animal products who may not get enough vitamin B-12, zinc, iron and calcium. It is also recommended that women who are pregnant or are breast-feeding take additional vitamins.
The famous cancer researcher Bruce Ames said that a multivitamin is an inexpensive form of medical insurance. At a cost of a few cents a day this "nutritional insurance" makes sense and it is for that reason that I take one myself. The Harvard School of Public Health agree and have stated that…"looking at all the evidence, the potential health benefits of taking a standard daily multivitamin seem to outweigh the potential risks for most people."
* Ref: Best Practice Journal; 2011;BPJ: 36, "Vitamin D supplementation: Navigating the debate”