The Roles and Functions of Vitamins and Minerals In Adults

Introduction to vitamins and minerals

With increasing focus placed on additional supplements and vitamins on top of our regular diet, we have been seeing an increase in the sales of supplements and vitamins. The global market has seen a 6.3% increase from 2014 to 2018 and is expected to grow further [1]. Despite taking all these vitamins and minerals, do you know what are the roles and functions of these vitamins? Read on to find out more.

Vitamin A

Vitamin A is a fat-soluble vitamin which is best known for its function on the human body’s vision [2]. It also plays a role in cell growth and differentiation, maintaining normal functions of several organs like the heart and lungs [3]. There are 2 different types of vitamin A: (1) pre-formed vitamin A which is found in meat and fish, and (2) provitamin A which is found in plant-based products [2]. The recommended daily allowance of vitamin A for a healthy adult is about 700mcg to 900mcg retinol activity equivalent (RAE) [4].

Vitamin B

Vitamin B class consists of a total of 8 sub-groups of vitamin B:

• B1: Thiamine
• B2: Riboflavin
• B3: Niacin
• B5: Pantothenic acid
• B6: Pyridoxine
• B7: Biotin
• B9: Folate / Folic acid
• B12: Cobalamin

B6: Pyridoxine

Vitamin B6, also known as pyridoxine, has been widely studied in the prevention of some diseases, including cardiovascular diseases and cognitive functions [5]. Trials and studies have also shown that vitamin B6 is able to help reduce nausea and vomiting in pregnancy [6]. It can be found in food sources such as tuna, salmon and dark leafy vegetables [5]. The recommended daily allowance (RDA) for vitamin B6 is 1.5mg [7].

B9: Folate / Folic acid

Vitamin B9, also known as folate or folic acid, is well-known as a pregnancy supplement. Folate is crucial in periods of rapid growth such as pregnancy due to its role in the formation of DNA, protein metabolism, and red blood cell production [8]. It is often found in dark leafy vegetables, fresh fruits, and seafood [8]. The RDA for folate is 400mcg DFE (dietary folate equivalent), and up to 600mcg DFE for pregnant ladies [7].

B12: Cobalamin

Vitamin B12, also known as cobalamin, exists in multiple forms: biologically active forms include methylcobalamin and 5-deoxyadenosylcobalamin, while hydroxycobalamin and cyanocobalamin are precursors of the active forms which gets converted in the body [9]. It helps with red blood cell production, energy metabolism and possibly involvement in cognitive functions [10]. Dietary sources of cobalamins include shellfish, red meat and eggs [10]. The RDA for a healthy adult is 2.4mg.

Vitamin C

Vitamin C, also known as ascorbic acid, is known for its effects and roles in boosting the body’s immunity system and wound healing. For more information on vitamin C, follow and click on our article that discussed the multiple functions in greater details.

Vitamin D

Vitamin D, also known as calciferol, has been traditionally used for bone health due to its effects on increased calcium absorption. Recently, there are also data suggesting its role in immunity as well. For more information on vitamin D, follow and click on our article that discussed the multiple functions in greater details.

Vitamin E

Vitamin E is a group of 8 fat-soluble chemicals that have distinct antioxidant properties [11]. The only chemical that has activity to meet human requirements is the alpha-tocopherol [11]. Vitamin E has antioxidant properties that can protect cells from the oxidative stress of free radicals. Vitamin E is also involved in the immune system, as well as the regulation of several metabolic processes [12]. Good sources of vitamin E includes plant oils like sunflower oil and corn oil, and nuts such as almond and peanuts [13]. The RDA for vitamin E for a healthy adult is 15mg [14].

Iodine and Zinc

Iodine is a mineral found in foods such as seaweed, fish, and some seafood [15]. It is an essential component of the thyroid hormones which are responsible for several metabolic processes in our body [15]. Iodine supplementation is also critical for foetus development during pregnancy [15]. The RDA for iodine for a healthy adult is 150mcg and increases to 220mcg in pregnancy and lactation [4].

Zinc is another essential mineral found naturally in certain foods like seafood and meat [16]. Zinc is involved in certain cellular processes such as the immune function, protein synthesis, and cell division [16]. The RDA for zinc for a healthy adult is 11mg [4].

Conclusion

As the world progresses and people’s health knowledge advances, the usage of such multivitamins and supplements will only see an increase in the future. It is thus crucial to understand more about these vitamins and minerals present in these supplements and find out about their functions and recommended daily amount to be taken.

References

1. PwC Analysis, Technavio 2019, Press. Available on: https://www.pwc.com/it/it/publications/assets/docs/Vitamins-Dietary-Supplements-Market-Overview.pdf
2. National Institutes of Health (NIH), Office of Dietary Supplements. Vitamin A: Fact Sheet for Health Professionals. 2021 March. Available on: https://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/
3. Ross CA. Vitamin A. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. London and New York: Informa Healthcare; 2010:778-91.
4. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press; 2001.
5. Harvard T.H. Chan School of Public Health. The Nutrition Source: Vitamin B6. Available on: https://www.hsph.harvard.edu/nutritionsource/vitamin-b6/
6. McParlin C, O’Donnell A, Robson SC, et al. Treatments for hyperemesis gravidarum and nausea and vomiting in pregnancy: a systematic review. JAMA. 2016 Oct 4;316(13):1392-401.
7. Institute of Medicine. Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. Washington, DC: National Academy Press, 1999.
8. Harvard T.H. Chan School of Public Health. The Nutrition Source: Vitamin B9. Available on: https://www.hsph.harvard.edu/nutritionsource/folic-acid/
9. National Institutes of Health (NIH), Office of Dietary Supplements. Vitamin B12: Fact Sheet for Health Professionals. 2021 March. Available on: https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/
10. Harvard T.H. Chan School of Public Health. The Nutrition Source: Vitamin B12. Available on: https://www.hsph.harvard.edu/nutritionsource/vitamin-b12/
11. National Institutes of Health (NIH), Office of Dietary Supplements. Vitamin E: Fact Sheet for Health Professionals. 2021 March. Available on: https://ods.od.nih.gov/factsheets/VitaminE-HealthProfessional/
12. Traber MG. Vitamin E. In: Shils ME, Shike M, Ross AC, Caballero B, Cousins R, eds. Modern Nutrition in Health and Disease. 10th ed. Baltimore, MD: Lippincott Williams & Wilkins, 2006;396-411.
13. 20 Foods That Are High in Vitamin E. 2017 May. Available on: https://www.healthline.com/nutrition/foods-high-in-vitamin-e
14. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000.
15. National Institutes of Health (NIH), Office of Dietary Supplements. Iodine: Fact Sheet for Health Professionals. 2021 March. Available on: https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/
16. National Institutes of Health (NIH), Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals. 2021 December. Available on: https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/