Food supplements are a broad category of products used for a wide range of reasons. Below are the most popular and well-supported examples.
The most commonly purchased supplements from this category are vitamin supplements. Most of these are relatively straightforward and so we won’t dwell too long on these or break them all down individually. Micronutrient supplements are offered in single form, a bundled form to take advantage of combinatorial benefits (for example vitamin D helps with calcium metabolism and so these are often seen together) or as a broad-spectrum multivitamin.
Single vitamin products are the easiest to justify the use of. These products are efficacious when used, to solve a nutritional deficiency caused by incomplete nutrition. If, for example, your diet is low in calcium because you don’t consume many calcium-containing foods, then a calcium supplement can help to increase plasma calcium levels and will help you avoid the effects of calcium insufficiency. There is strong evidence for this – for example it has been shown in men who are given a diet which promoted zinc deficiency, that subject sperm count was impacted (zinc is required for sperm production) but subsequent supplementation corrected this issue.
Paired nutrient supplements are also effective, but equally a single micronutrient supplement taken alongside a meal is likely to be consumed alongside other nutrients and, as this is typically the recommended means of taking these supplements, it may not be necessary to spend the extra money.
Broad spectrum multivitamins are an excellent ‘safety net’ or ‘insurance policy’ in that they can be taken alongside a normal diet in to avoid micronutrient shortfalls. These have not been shown to be harmful in any way by long-term research, and their mechanism of action is clear. Taking a broad-spectrum multivitamin is something worth considering unless your diet is extremely varied and all-encompassing.
As mentioned in module 3, micronutrients are extremely important and a deficiency in one can have effects more wide-reaching than might be expected, so using supplementation to avoid this could be wise. What is important to bear in mind for the context of this module, however, is that micronutrient supplements do not improve any marker of health per se. It can often be claimed that certain vitamins or minerals will ‘boost your immune system’ or ‘improve skin tone’ but it’s important to remember that this only happens to the extent that the ideal intake of a nutrient (as defined in module 3) would cause anyway.
This is critical – micronutrient supplements do not cause benefits, they simply allow you to ensure a sufficient intake. Therefore, you get the inherent benefits of the thing you are supplementing. Ingesting amounts over and above what is useful does not give anything more, and in fact supplementation of certain nutrients (most notably trace minerals and vitamin A) which results in an excessive intake can lead to harmful effects so high-dose supplementation beyond what is stated in module 3 is not recommended. If you are concerned that you may be deficient in a certain nutrient, a blood test from a GP will enable you to find out. For a less invasive approach a micronutrient tracking app should be able to help you pinpoint shortfalls in your regular diet.