Every day, our bodies work around the clock orchestrating thousands of different tasks that keep us alive and functioning well. These range from continuously delivering enough oxygen to our cells, to making sure that our immune system is ready to fight potentially harmful invaders.
To carry out all its functions, our body needs specific nutrients that come from the foods we eat. While most of our bodies’ fuel and building blocks are provided by so-called macronutrients (carbohydrates, fats and proteins), each particular function and process requires a delicate balance between tiny amounts of other nutrients, called micronutrients.
What are vitamins?
Simply put, vitamins are organic compounds produced by bacteria, plants and animals, which are essential to human health. The name itself comes from the Latin word “vita”, which means life.
Out of the 14 necessary vitamins, our bodies can produce 3 of them – vitamin D, niacin and choline – however, not in amounts that allow us to be self-sufficient. Thus, we still need to include all vitamins in our diet. Vitamins can be classified as water- or fat-soluble, depending on their ability to dissolve in water or fat, respectively. This in turn affects the way they’re absorbed, transported and stored in the body.
Water-soluble vitamins are essential to human health, that dissolve in water and are present in the watery parts of food. Generally, water-soluble can’t be stored in the body for long periods and are rapidly removed through urine when present in excess. They include thiamin, riboflavin, niacin, pantothenic acid, vitamin B6, biotin, folate, vitamin B12 and vitamin C. They are present in the watery parts of the food we eat and are easily absorbed into our bodies. Our bodies can’t store most water-soluble vitamins for long periods and quickly remove any excess through urine, except for vitamin B12, which we can store in significant amounts in our liver and kidneys. 1
Fat-soluble vitamins dissolve in fats and oils, thus are abundant in foods rich in fats such as vegetable oils, fatty fish or full-fat dairy. In turn, fat-soluble vitamins from vegetable sources are usually better absorbed when paired together or cooked with fat-rich foods. Contrary to water-soluble vitamins, our bodies can store some of these vitamins in the liver and fat tissues and use them as needed.1,2
Water-soluble vitamins have a key role in helping our bodies convert the different foods we eat into energy that can be used by our cells. They are also involved in the proper functioning of our nervous system and they help our cells multiply while protecting our genetic material (DNA) in the process.
As for the four fat-soluble vitamins, while they’re involved in many important functions, they each have a starring role in the body. For example, vitamin A is important for normal vision; vitamin D helps regulate the levels of calcium and phosphorus in the body; vitamin E has a key role in protecting cells from free-radicals and vitamin K is essential for blood clotting.
What are minerals?
There are many minerals in nature, however, our bodies only need 14 of them to survive. Minerals are inorganic compounds that originate from non-living matter, such as rocks, soil, or water. We get them in our diet directly through water, or indirectly through eating plants and animal-based foods, when they absorb it from the environment or through the food chain.
We can divide essential minerals in major minerals or trace elements, depending on their chemical structure and how much we need them in our diets.
- Major or macro-minerals are needed in relatively large amounts, usually above 200 mg, or even a few grams per day, to keep our health.
- Trace elements, sometimes also referred to as micro-minerals, are needed in much smaller amounts, usually below one milligram (micrograms), or a few milligrams mg per day, to keep our health.
How do vitamins and minerals work in the body?
It’s common to look at micronutrients as individual players, but it’s their continuous interactions that allow us to thrive. In fact, despite their differences, vitamins and minerals often work together to perform specific tasks in our bodies. Take vitamin B12 and folate for example. This precious duo works together to create healthy blood cells. But without iron or phosphorus and chloride, the oxygen from the lungs could not hop on (and off) the red blood cells to be delivered around the body.
In other cases, micronutrients team up in unexpected advantageous ways. For example, vitamin C can give our gut a helping hand to absorb the iron from plant-based foods, which we naturally absorb less than the iron from animal products.
However, the opposite dynamics can also happen, too much of a specific micronutrient can hinder levels of another, either by competing for absorption or by pushing the other to be removed out of the body. For example, a diet high in table salt (i.e. sodium chloride) can reduce the level of calcium in our bodies, as calcium binds to sodium to help the body get rid of the salt surplus. As so, respecting the recommended amounts of salt in our diets, is important not only to lower the risk of cardiovascular diseases but also to protect the health of our bones.
Considering that virtually every single function in our bodies depends on a good balance of several vitamins and minerals, ensuring the right amounts is key. But how much of each micronutrient do we need and what happens if we fall far below or above the recommended amounts?
How much of each micronutrient do we need?
How much of each vitamin and mineral we need to keep healthy depends on our age, sex and physiological state (i.e. during pregnancy or lactation). The values that guide nutrient recommendations are known as the dietary reference values (DRVs).6
Simply put, DRVs estimate how much of each nutrient, on average, is needed on a daily basis to support the adequate growth, development and health of healthy population groups. However, DRVs should not be interpreted as nutrient goals; they are used by professionals to provide nutritional advice to specific individuals or groups.6
Countries use DRVs to set their nutritional recommendations which also account for other factors such as the traditional diet of the country or the duration of sunlight. 7 Hence, following your country’s dietary guidelines is the safest way to meet your vitamins and minerals needs, without risking having too little or too much of them.
- Bender A.D. 2015. Micronutrients: Vitamins & Minerals. In: Rodwell, W.V., Bender, A.D., Botham, M.K., Kennelly, J.P. and Weil, A. P. 2015. Harper’s Illustrated Biochemistry. 30th edition. McGraw-Hill Education, pp 546-563.
- World Health Organization (WHO). 2004. Vitamin and mineral requirements in human nutrition. 2nd edition. Geneva, Switzerland: WHO.
- European Food Safety Authority. 2015. Scientific Opinion on Dietary Reference Values for phosphorus. EFSA Journal 2015;13
- European Food Safety Authority. 2019. Scientific Opinion on dietary reference values for chloride. EFSA Journal 2019;17(9):5779
- European Food Safety Authority. 2015. Scientific Opinion on Dietary Reference Values for calcium. EFSA Journal 2015;13
- European Food Safety Authority. 2010. Scientific Opinion on principles for deriving and applying Dietary Reference Values. EFSA Journal 2010; 8(3):1458
- Doets E.L. et al., 2008. Current micronutrient recommendations in Europe: towards understanding their differences and similarities. European Journal of Nutrition; 2008;47(1)