Minerals and vitamins are usually classified as micronutrients and have numerous health benefits such as formation and health of teeth and bone, help coordination and regulation of most body functions, tissue maintenance, serve as coenzymes and cofactors, among other physiological and biochemical processes in the body. Humans and other organisms need micronutrients in different amounts to aid in maintaining health through coordination of physiological health. In contrast to macronutrients that humans require in grams per day, micronutrients such as vitamins and minerals are required in less than 100 mg per day. However, living organisms cannot synthesize minerals such as iron and calcium, which humans and animals obtain from the soil. Since humans and other animals primarily get nutrients from plants, deficiencies can develop due to some micronutrients in small quantities, even in plants, when the dietary intake is insufficient.
Vitamins are organic compounds and essential micronutrients that organisms such as humans need in small amounts, ranging from micrograms to milligrams, to help in the effective functioning of the organism’s metabolism. Usually, the human body cannot entirely or insufficient amount, synthesize or make essential nutrients just like beneficial phytochemicals, hence should be obtained from the diet. There are thirteen vitamins necessary for the metabolic functions of humans. They include vitamin A, vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folate), vitamin B12 (cobalamins), vitamin C (ascorbic acid, vitamin D (calciferol), vitamin E (tocotrienols and tocopherols), and vitamin K (quinones) (Shankar, 2001).
These vitamins have numerous and distinct biochemical functions in the body. Vitamin A is critical to tissue and cell growth regulation, and differentiation and B vitamins act as coenzymes and cofactors or their precursors. Vitamin D has a function similar to hormones, where they help in the regulation of mineral metabolism for some organs and bones in the body. Vitamin C and E function as antioxidants by preventing free radicals from oxidizing cells in the body (Shankar, 2001). Thus, both excessive and deficient intake of vitamins might lead to clinically significant diseases. However, it is unlikely to develop such illness through excess intake of water-soluble vitamins. Also, the body uses vitamins for disease prevention, proper growth, and immune system efficacy improvement. They are usually taken routinely with diet in trace amounts to sustain the immune system’s barriers, including cell-mediated, skin, and humoral immune response. The immunity system is responsible for the prevention of the body’s active tissues from agents that result in diseases.
Bioavailability is commonly described as the availability of vitamins in blood circulation and their impact on the human body. Broadly, it is identified as the proper absorptivity and the uptake of numerous nutrients by the cells. It is affected by factors such as sex, age, and physiological conditions, e.g., pregnancy (Aslam et al., 2017). Disturbances in vitamin utilization and absorption and insufficient vitamin intake are the major causes of vitamins. Malnutrition leads to weakened immunity resulting in weakened immunity and chronic infections due to weakened immune response. Moreover, dietary intake of vitamins can be reduced by food ingestion and eating disorders such as binge eating and bulimic condition.
Vitamin bioavailability is also dependent on the amount and type of nutrients digested together with them in the body, such as caffeine and phytates, which reduce mineral and vitamin absorption. In some instances, a decrease or increase in one vitamin affects the absorption of other vitamins. For example, when working together with vitamin B6, B9, and B12, enhance vitamin absorption, and their reduced quantity might affect others. Also, some drugs such as histamine, antibiotics, anti-seizure, anti-inflammatory, etc., reduces the levels of vitamin C and D and vitamin B complex in the body cells. Some known diseases, including lactose intolerance and celiac disease, decrease the absorption in the body through interferences in the digestive processes such as incomplete digestion.
Biochemical functions of vitamins
One of the significant biochemical functions of vitamins is fetal growth and childhood development. A fetus develops through absorbing nutrients using the genetic blueprint it inherits from parents. Fetuses at certain times require some minerals and vitamins, which are crucial to the facilitation of biochemical reactions that produce bone, skin, muscles, among others (Aslam et al., 2017). A child can develop deficiency disease-causing permanent damage if these micronutrients are deficient. Once a human has fully grown and developed, vitamins stay essential in maintaining healthy organs, cells, and tissues in a multicellular organism. Moreover, they enable the sufficient and efficient use of chemical energy obtained from diets besides helping in the processing of macronutrients essential to cellular respiration.
From a nutritional perspective, minerals are inorganic elements that organisms like humans require as essential nutrients to help in carrying out functions vital for life. However, oxygen, carbon, hydrogen, and carbon, which make up almost 96% of the human body weight, are not considered significant nutrient minerals (Gombart, Pierre, & Maggini, 2020). The remainder of the human body weight is accounted for by major and minor minerals. Sodium, potassium, calcium, phosphorous, and magnesium are the major minerals, while minor (trace) minerals include iron, copper, iodine, zinc, sulfur, manganese, among others (Gombart, Pierre, & Maggini, 2020). Due to their existence as elements, humans cannot biochemically synthesize them. Thus, minerals in the human diet originate from either drinking water and eating plants and animals.
Humans and other organisms consume most chemical elements in the form of simple compounds. Plants obtain dissolved elements through absorption from soils, where herbivores and omnivores subsequently consume them by eating the plants, hence moving up the food chain. Also, larger organisms can use the mineral resources or ingest soil to get minerals that other dietary sources cannot obtain. Within the ecological food chain, fungi and bacteria are responsible for breaking down primary elements’ consumption and other species’ consumption. Minerals are crucial in biomineralization, where organisms mineralize structures to form shells, bones, and exoskeleton.
Nutritionists and dietitians recommend consuming food rich in certain elements is the best supply of minerals in the body. Moreover, minerals may be added to diets such as iodized salt fortified with salt or naturally present in the diet, e.g., calcium in milk. The focus of dietary on chemical elements stems from evidence that they support metabolic biochemical reactions with required elemental components. Studies have shown that some chemical elements’ inappropriate intake levels are essential for optimal health maintenance.
Role Of Vitamins And Minerals In Immune Function
Vitamins and minerals are essential to creating physical and biochemical barriers such as skin and all mucus membrane against pathogens and other harmful substances. Vitamins and minerals play a crucial role in the maintenance of these physical barriers for optimal function. For example, zinc and vitamin A help maintain skin and mucosal cells’ functional and structural integrity. Also, vitamin E and C as antioxidants combine with endogenous antioxidant defenses in the body to maintain cell’s physiological levels, thus restoring cell signaling and protecting them from damage (Fairfield & Fletcher, 2002). Iron is crucial to the growth and differentiation of epithelial tissue.
These micronutrients also form part of the body’s innate immunity by contributing to the inflammatory process a pathogen enters the body as antimicrobial substances. One of these antimicrobial substances is interferons that prevent the replication of a virus in the human body. Micronutrients such as zinc, vitamin C, and iron are essential to interferon production, while vitamin A and selenium increase and decrease their production, respectively. Also, vitamins and minerals help boost a body’s immunity by activating and maintaining phagocytes and natural killer cells. NK cells target and kill pathogens’ cells using cytotoxins. Its function and number are regulated with the help of vitamin A. Zinc together with folate and vitamins C, B6, E, B12, enhance or maintain the cytotoxic activity of NK cells (Meydani & Han, 2001). Also, calcitriol is responsible for phagocytosis, which kills microbes in the body. Moreover, micronutrients help repair damaged tissues by pathogens and other substances due to their role in the inflammatory response. For example, vitamin C decreases histamine levels and modulates cytokine production while vitamin E reduces prostaglandin E2, which has immunosuppressive activity production.
The human body needs micronutrients in optimal levels for immune function effectiveness. Various studies have shown that clinical micronutrients significantly impact the immune system leaving individuals susceptible to infections. For example, there is an increased risk of mortality and morbidity with all common diseases when there is micronutrient deficiency. However, the duration and extent of micronutrient deficiency affect the severity of any adverse health effects.
Aslam, M. F., Majeed, S., Aslam, S., & Irfan, J. A. (2017). Vitamins: Key role players in boosting up immune response—A mini-review. Vitam Miner, 6(1), 2376-1318.
Fairfield, K. M., & Fletcher, R. H. (2002). Vitamins for chronic disease prevention in adults: scientific review. Jama, 287(23), 3116-3126.
Gombart, A. F., Pierre, A., & Maggini, S. (2020). A review of micronutrients and the immune system–working in harmony to reduce the risk of infection. Nutrients, 12(1), 236.
Meydani, S. N., & Han, S. N. (2001). Nutrient regulation of the immune response: the case of vitamin E. Present Knowledge in Nutrition, 8th Ed., Bowman, B. and R. Russell, eds., Washington, DC, 449-463.
Shankar, A. H. (2001). Nutritional modulation of immune function and infectious disease. Present knowledge in nutrition, 686-700.