Micronutrient: a chemical element or substance required in trace amounts for the normal growth and development of living organisms.

​Micronutrients are vitamins and minerals required in small amounts that are vital for maintaining health, preventing diseases, and ensuring proper body function. Unlike macronutrients (carbohydrates, proteins, and fats), which provide energy, micronutrients are essential for numerous physiological functions.

Why micronutrients are important

While macronutrients provide the energy necessary for daily activities, micronutrients are vital for the body's metabolic processes, disease prevention, and overall health. Here's why focusing on micronutrients can be more crucial:
  1. Disease Prevention: Micronutrient deficiencies can lead to a range of health issues, from anemia (iron deficiency) to scurvy (vitamin C deficiency) and osteoporosis (calcium and vitamin D deficiency).
  2. Immune Support: Vitamins such as A, C, D, and E and minerals like zinc and selenium play significant roles in maintaining a robust immune system.
  3. Bone Health: Minerals like calcium, magnesium, and phosphorus are essential for maintaining strong bones and preventing osteoporosis.
  4. Antioxidant Protection: Vitamins C and E and minerals like selenium protect the body from oxidative stress and free radical damage.
  5. Metabolic Regulation: B vitamins and minerals like chromium and magnesium are crucial for efficient energy metabolism and overall cellular function.

​Ensuring adequate intake of both vitamins and minerals is essential for optimal health and well-being. While macronutrients provide the necessary energy for our bodies, micronutrients are the foundation for preventing disease, supporting immune function, and maintaining overall physiological health. By prioritizing a balanced diet rich in fruits, vegetables, whole grains, and lean proteins, you can ensure that you receive the essential micronutrients your body needs.

Influence of Micronutrients on Bone and Muscle

Mirconutrients, vitamins and minerals, are essential for wide variety of functions within the human body. In fact, athletes actually need more micronutrients because the demands placed on the body through intensified physical activity. A higher percentage of micronutrients are needed because of increased loss from sweating, decreased nutrient absorption, and increased tissue repair/maintenance (Lorincz, Manske, & Zernicke, 2009). Most notably, calcium and vitamin D are crucial in promoting healthy bone. Other important micronutrients that influence bone health include vitamin B6, vitamin B12, vitamin C, folate, fluoride, iron, magnesium, sodium and zinc. Micronutrients that influence muscle are calcium, choline, B vitamins, vitamin C, vitamin E, iron, magnesium, phosphorus and zinc.

overview of Vitamins

  • Vitamin A: Supports vision, immune function, and skin health.
  • Vitamin C: Important for skin, bones, and connective tissue; antioxidant.
  • Vitamin D: Supports bone health by aiding calcium absorption.
    • Ergocalciferol
    • Cholecalciferol
  • Vitamin E ​(tocopherols and tocotrienols): Acts as an antioxidant, protects cell membranes.
  • Vitamin K: Essential for blood clotting and bone health.
    • Vitamin K1 (phylloquinone)
    • Vitamin K2 (menaquinone)
    • Vitamin K3 (menadione)
  • B Vitamin Complex:
    • B1 (Thiamine): Energy metabolism, nerve function.
    • B2 (Riboflavin): Energy production, skin health.
    • B3 (Niacin): Digestive health, skin, nerves.
    • B5 (Pantothenic Acid): Hormone production, energy metabolism.
    • B6 (Pyridoxine) Group: Amino acid metabolism, red blood cell production.
      • Pyridoxine
      • Pyridoxal-5-Phosphate
      • Pyridoxamine
    • B7 (Biotin): Metabolism of fats, carbs, and proteins.
    • B9 (Folate/Folic Acid): DNA synthesis, cell division, and red blood cell formation.
    • B12 (Cobalamin): Nerve function, red blood cell production.
    • B17 (Amygdalin): controversially accepted as a vitamin, and boosts immunity
  • Vitamin H (Biotin): Supports metabolism of fats, carbohydrates, and proteins.
  • Choline: ​​Essential for liver, brain and blood health.

overview of minerals

  • Calcium: Bone health, muscle function, nerve signaling.
  • Sulfur: Contained within amino acids (cysteine and methionine)
  • Iron: Red blood cell formation, oxygen transport.
  • Magnesium: Muscle and nerve function, energy production.
  • Phosphorus: Bone and teeth formation, energy metabolism.
  • Potassium: Fluid balance, nerve transmission, muscle contraction.
  • Sodium: Fluid balance, nerve transmission, muscle function.
  • Zinc: Immune function, wound healing, DNA synthesis.
  • Trace Elements
    • Copper: Iron metabolism, connective tissue formation.
    • Boron: Reduces inflammation.
    • Manganese: Bone formation, energy metabolism, antioxidant function.
    • Selenium: Antioxidant protection, thyroid function.
    • Iodine: Thyroid hormone production, metabolic regulation.
    • Chromium: Enhances insulin action, glucose metabolism.
    • Molybdenum: Enzyme function, amino acid metabolism.
    • Fluoride: Bone and dental health.
    • Chloride: Fluid and acid-base balance, muscle contraction, and nervous function.
    • Silicon: Bone mineral density.
    • Cobalt (as a component of vitamin B12): acts as a cofactor for enzymes.
Picture
The Periodic Table and the Required Trace and Major Minerals Six major minerals and at least eight trace minerals are vital for health and are therefore essential nutrients.

Vitamins 

Vitamin A
Vitamin A is a fat-soluble nutrient critical for numerous physiological functions. While it is often associated with vision, its role extends far beyond eyesight. Retinol, the active form of vitamin A, is essential for cellular health, mitochondrial energy production, immune function, and overall systemic balance. This article will explore the fundamental functions and benefits of retinol, its impact on mitochondria, and how it differs from beta-carotene.

One of retinol’s most overlooked yet crucial roles is in mitochondrial function and energy metabolism. Mitochondria, the powerhouse of the cell, rely on vitamin A to generate ATP, the body's primary energy currency. Retinol influences mitochondrial respiration, ensuring efficient ATP production. It acts as an antioxidant, reducing oxidative damage within mitochondria, which is vital for preventing premature cellular aging. Retinol is involved in the regulation of mitochondrial gene expression, optimizing energy metabolism and reducing metabolic disorders. The thyroid gland regulates energy metabolism, and vitamin A helps facilitate the conversion of T4 (inactive thyroid hormone) into T3 (active thyroid hormone), directly influencing energy levels. A deficiency in retinol can result in mitochondrial dysfunction, leading to fatigue, poor cellular repair, and metabolic issues.

Other Critical Functions of Retinol
  1. Immune System Regulation
  2. Skin Health and Anti-Aging
  3. Eye Health and Vision Support
  4. Hormonal Balance and Fertility
  5. Bone Health and Growth

While both retinol and beta-carotene are classified as forms of vitamin A, they are fundamentally different in terms of absorption, function, and bioavailability.

Vitamin D
Vitamin D is an essential chemical messenger that controls calcium levels within the blood. When calcium levels within the blood are low, vitamin D can enhance calcium absorption within the intestines. In addition, Vitamin D is able to send messages to breakdown existing bone and release calcium into the blood stream. When calcium levels within the blood are too high, vitamin D can assist in removing calcium from the blood by stimulating a bone forming process. Vitamin D3, the preferred form of Vitamin D, can be created within the skin via the interaction of sunlight, or ultraviolet radiation, and a couple Vitamin D precursors. Vitamin D3 can also be obtained through diet, in an inactive form, which is eventually converted in the liver to become active. The current daily adequate intake for vitamin C is 200 IU/day for adults up to 50 years of age, 400 IU/day for adults between 51-70 years of age, and 600 IU/day for adults over 71 years of age. However, researchers suggest at least 1000-4000 IU/day to ensure adequate protective health effects. Sources of vitamin D include regular sun exposure (about 2 times/week with the arms and legs exposed 5-30 minutes depending on season, latitude and skin pigmentation) or vitamin D3 supplementation (Lorincz, Manske, & Zernicke, 2009). Other sources of vitamin D include salmon, sardines and tuna (Mateljan, 2001).

Vitamin E
Vitamin E is another antioxidant, that is known to reduce free radicals, which are highly reactive molecules that causes oxidative damage to cells. Inconsistent research supports whether or not vitamin E may also reduce DOMS (Maes & Kravitz, 2003). However, other research has supported vitamin E enhancing the utilization of oxygen at high altitudes, by preventing the destruction of red blood cells (Williams, 2004). The current RDA for vitamin E is 15 mg/day for both adult men and women (Ross, Taylor, Yaktine, & Del Valle, 2011). Good sources of vitamin E include sunflower seeds, almonds, spinach, swiss chard and avocado (Mateljan, 2001).

B Vitamins
The B vitamins, including vitamin B6, vitamin B12 and folate, play an important role in growth and bone health. B vitamins, B1 (thiamin), B6 (pyridoxine), B12 (methylcobalamin) and folate, play a direct role in metabolizing macronutrients. The B vitamins aid in the metabolism of an amino acid called homocysteine. Although the mechanism is not exactly clear, researchers have determined that high concentrations of homocysteine in conjunction with low levels of vitamin B12 and folate are associated with low BMD, and a higher risk of fractures in the geriatric population. B vitamins can be obtained through both plant (besides vitamin B12) and animal sources. While deficiency of B vitamins impairs physical performance, supplementing with B-vitamins does not seem to enhance performance (Williams, 2004). The recommended dietary allowance (RDA) for vitamin B6 is 1.3 mg/day for both men and women between the ages of 19-50. Good sources of vitamin B6 include fish, chicken, nuts, legumes, potatoes and bananas. The RDA for thiamin is 1.1 mg/day for females and 1.2 mg/day for males. Good sources of thiamin include pork, whole grains, legumes, tuna, soy milk. The RDA for folic acid (folate) is 400 μg/day for men and women of all ages. Good sources of folate include green leafy vegetables, citrus fruits and legumes. The RDA for vitamin B12 is 2.4 μg/day for men and women of all ages. Vitamin B12 can only be obtained through animal sources. Good sources of vitamin B12 include clams, mussels, mackerel, beef, salmon and eggs (Fratoni & Brandi, 2015).

Biotin
Biotin, a water-soluble vitamin, is used as cofactor of enzymes involved in carboxylation reactions. In humans, there are five biotin-dependent enzymes which catalyze key reactions in gluconeogenesis, fatty acid metabolism, and amino acid catabolism; thus, biotin plays an essential role in maintaining metabolic homeostasis. In recent years, biotin has been associated with several diseases in humans. Humans are unable to synthesize biotin and thus depend entirely on the vitamin present in foods to satisfy their vitamin requirements. Most notably, biotin is responsible for hair growth due to it's role in keratin production. Keratins have important regulatory functions, including protection from stress, apoptosis, and wound healing. Additionally, biotin has been demonstrated to mitigate inflammation and improve diabetic peripheral neuropathy. 
Food
Serving Size
Amount (mg)
DRI/DV (%)
Peanuts
0.25 cup
26.3
87.6
Tomatoes
1 cup
7.2
24
Almonds
0.25 cup
14.7
49.1
Eggs
1 each
8.0
26.7
Onions
1 cup
8.0
26.6
Carrots
1 cup
6.1
20.3
Romaine Lettuce
2 cups
1.8
6.0
Cauliflower
1 cup
1.6
5.4
Sweet Potato
1 medium
8.6
28.7
Oats
0.25 cup
7.8
26.0

Vitamin C
Vitamin C is an antioxidant required for the synthesis of collagen, the largest component in the organic portion of bone. Collagen also serves to function as the connective tissue forming layers within the muscle, which is divided into three categories: epimysium, perimysium, and endomysium (Birch, MacLaren, & George, 2004). Research conducted on animals demonstrates that vitamin C deficiency is correlation with impaired bone bass, cartilage and connective tissue. In addition, research as concluded that there is a positive correlation between vitamin C intakes and BMD at multiple bone sites. Researchers suggest that vitamin C may also decrease oxidative stress, which may help prevent osteoporosis (Sahni et al., 2008). As an antioxidant, vitamin C helps reduce oxidative damage to cells and enhances the immune system. Thus, vitamin C has been shown to improve performance in deficient subjects, but this effect is not seen in well-nourished athletes (Kreider et al., 2010), (Williams, 2004). While research in inconsistent, vitamin C may potential treat or reduce delayed onset muscle soreness (DOMS), which is characterized as soreness, stiffness, inflammation, and/or pain that may occur after an acute resistance training session (Birch, MacLaren, & George, 2004), (Maes & Kravitz, 2003). The current RDA for vitamin C is 90 mg/day and 75 mg/day, respectively for adult men and women. Since smoking increases oxidative stress and the metabolism of vitamin C, smokers are advised to increase vitamin C intake by 35 mg/day (Krinsky et al., 2000). Good sources of vitamin C include papaya, bell peppers, broccoli, Brussels sprouts, strawberries, pineapple, oranges and kiwi (Mateljan, 2001).

Minerals

Choline
Choline is an essential micronutrient required for the structure of cell membrane and is required to form actlycholine (Ach), a neurotransmitter released in skeletal muscle. Ach begins a series of chemical events that cause the muscle to contract (Birch, MacLaren, & George, 2004). A reduction of Ach is theorized to contribute to fatigue, thus suggesting that supplementing choline may reduce fatigue. However, research suggests choline does not prolong aerobic training (Williams, 2004). Good sources of choline include shrimp, eggs, scallops, chicken, turkey, tuna, cod and salmon (Mateljan, 2001)

Calcium
Calcium is required for a number of physiologic processes including muscle contraction, nerve impulse transmission, and for maintaining hydroxyapatite, the inorganic portion of bone mainly composed of calcium and phosphate. The optimal calcium intake for young adults is 1200 mg/day, for women between the ages of 25-50 years is 1000 mg/day, and 1500 mg/day for postmenopausal women (not of hormone replacement therapy) or women who are at risk of developing amenorrhea. Athletes have a higher risk for calcium deficiency, a status which can negatively affect bone health and physical performance (Lorincz, Manske, & Zernicke, 2009). Good sources of calcium include tofu, sardines, sesame seeds, dairy products, collard greens and spinach (Mateljan, 2001).
Food
Serving Size
Amount (mg)
DRI/DV (%)
Tofu
4 oz
774.5
77.5
Collard Greens
1 cup
267.9
26.8
Spinach
1 cup
244.8
24.5
Turnip Greens
1 cup
197.3
19.7
Mustard Greens
1 cup
165.2
16.5
Beet Greens
1 cup
164.2
16.4
Bok Choy
1 cup
158.1
15.8
Yogurt
1 cup
296.5
30
Swiss Chard
1 cup
101.5
10
Kale
1 cup
93.6
9

Fluoride
Some research on fluoride has been shown to stimulate bone formation and increase bone density (Dure-Smith et al., 1991). However, it should be noted that fluoride should be consumed via food sources rather than via drinking water, as more recent research conducted on animals suggests that fluoride may decrease bone strength by altering the microarchitechture, thus increasing the risk of fracture (Doull et al., 2006). Fluoride has been shown to accumulate in tissues within the human body, including bone (Doull et al., 2006) and the pineal gland (Luke, 1997). The current adequate intake (AI) for fluoride is 3 mg/day for adult females and 4 mg/day for adult males (Ross, Taylor, Yaktine, & Del Valle, 2011). Most foods have concentrations of fluoride well below 0.05 mg/100 g, except fluoridated water (Young et al., 1997). Keep in mind, the chemicals used to fluoridate water (fluorosilic acid, sodium flurosilicate, sodium fluoride) are not naturally occurring (“NSF Fact Sheet on Fluoridation,” 2013).

Iron
Iron, serving as a component of hemoglobin, binds and carries oxygen within red blood cells. Adequate consumption of iron is suggested, as iron deficiency can lead to anemia, a condition with a decreased ability of the blood to carry oxygen. Research suggests that supplementation of iron does not enhance performance in those who meet the recommended intake (Kreider et al., 2010). The current RDI for iron is 8 mg/day for men and 18 mg/day for women (Ross, Taylor, Yaktine, & Del Valle, 2011). Good sources of iron include soybeans, lentils, spinach and sesame seeds (Mateljan, 2001).

Magnesium
Magnesium, an essential micronutrient for all living cells, plays many roles in the body as it required for more than 300 enzymes (including the ATP reaction) and is required for anaerobic/aerobic energy production. Magnesium is crucial for optimal bone and muscle health, as about 60% of magnesium is stored in bone, and about 30% of the magnesium within the body is found in skeletal muscle. Low levels of magnesium promotes osteoporosis. Magnesium deficiency is associated with fragile and brittle bones, microfractures, impaired mechanical properties and low grade inflammation. Research suggests magnesium deficiency impairs protein synthesis, cell reproduction, as well as many hormones and neurotransmitters. Magnesium depletion may also result in muscle cramps, hypertension and is linked to a variety of diseases within the cardiovascular and neuromuscular systems, as well as diabetes. Dietary recommendations for athletes is suggest to be at or above the current dietary reference intake (DRI) (Young et al., 1997). Most research suggest that supplementation of magnesium does not enhance performance unless a deficiency is present (Kreider et al., 2010). Diets rich in processed foods and poor in micronutrients result in inadequate dietary magnesium intake (Castiglioni, Cazzaniga, Albisetti, & Maier, 2013). The current dietary reference intake (DRI) for magnesium is 400 mg/day and 310 mg/day respectively for males and females between the ages of 19-30 (Ross, Taylor, Yaktine, & Del Valle, 2011). Good sources of magnesium include pumpkin seeds, spinach, soybeans, sesame seeds, quinoa, black beans, cashews and sunflower seeds (Mateljan, 2001).

Phosphorus
Phosphorus is essential in component of animal tissues, and is most commonly found in the form of phosphate. Phosphorus is a structural component of cell membranes and nucleic acids. Roughly 15 percent of the total phosphorus in the body is distributed in soft tissues, the remain 85 percent is within bone. Most foods, besides plant seeds, display an adequate phosphorus bioavailability. Phosphorus sources are ubiquitous and include nearly all foods that are naturally occurring (Young et al., 1997). The current RDI for phosphorus is 700 mg/day for both men and women (Ross, Taylor, Yaktine, & Del Valle, 2011).

Sodium
Sodium plays a very important role in body, however the concentration of sodium must be optimal as too much or too little can result in adverse effects. Consumption of too much sodium promotes urinary calcium excretion, which in turn may lead to increased bone loss (Heaney, 2006). The current AI for sodium is 2.3 g/day for adults (Ross, Taylor, Yaktine, & Del Valle, 2011).

Zinc
Zinc serves many functions within a variety of enzymes, such as supporting the structure of proteins, regulates gene expression, and assists growth and development (Russell et al., 2001). Regarding bone, zinc stimulates bone formation and collagen synthesis in osteocytes (Seo, Cho, Kim, Shin, & Kwun, 2010). Deficiency of zinc leads to impairment of growth and development (Russel et al., 2001). Supplementing of zinc appears to enhance immune function (Kreider et al., 2010). The current DRI for zinc is 8 mg/day for adult females and 11 mg/day for adult males (Ross, Taylor, Yaktine, & Del Valle, 2011). Good sources of zinc include beef, sesame seeds, pumpkin seeds, lentil, garbanzo beans and cashews (Mateljan, 2001)

References

Birch, K., MacLaren, D., & George, K. (2004). Instant notes in sport and exercise physiology. London: BIOS Scientific Publishers.
 
Castiglioni, S., Cazzaniga, A., Albisetti, W., & Maier, J. A. M. (2013). Magnesium and osteoporosis: Current state of knowledge and future research directions. , 5(8), . Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3775240/

Doull, J., Boekelheide, K., Farishian, B., Isaacson, R., Klotz, J., Kumar, J., & Limeback, H. (2006). Fluoride in Drinking Water: A Scientific Review of EPA’s Standards. Retrieved December 3, 2016, from The National Academies Press, https://www.nap.edu/read/11571/chapter/7#142
 
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