Dear Colleagues,

Dietary micronutrients that are required in small amounts for human health are known as trace minerals (or trace elements), and vitamins. These include chromium, copper, fluoride, iodine, iron, manganese, selenium, and zinc.

Minerals form only five percent of the typical human diet but are essential for normal health and function. Macrominerals are defined as minerals that are required by adults in amounts greater than 100 mg/day or make up less than one percent of total body weight. Trace elements (or trace minerals) are usually defined as minerals that are required in amounts between 1–100 mg/day by adults or make up less than 0.01 percent of total body weight. Ultra-trace minerals generally are defined as minerals that are required in amounts less than 1 microgram/day. Minerals have many roles in the body including the formation of bones and teeth, are essential components of body fluids and tissues, are a part of enzymes, and are involved in nerve function. People have different requirements according to age, sex, and physiological state (e.g., pregnancy, anemia). Mineral bioavailability is affected by many factors including body needs. Deficiencies of certain minerals are global health concerns. Ingestion of large doses leads to accumulation in the body and can be fatal. As such, recommended intakes for trace elements are expressed as Recommended Dietary Allowances (RDA) or Adequate Intake. The Upper Limit is the quantity of the nutrient considered to cause no adverse effects in healthy individuals. These parameters have been estimated for each trace mineral. Previous research demonstrated that: (1) Copper deficiency can be caused by an x-linked mutation of the transport protein mediating copper uptake from the intestine (Menkes disease). It can also be caused by malabsorption after gastrointestinal surgery (including gastric bypass for weight loss and gastric resection for malignancy or peptic ulcer disease), or by ingestion of high doses of zinc. Clinical manifestations include anemia, ataxia, and myeloneuropathy. (2) Iodine deficiency is characterized by goiter and hypothyroidism, which in turn has effects on growth, development, and cognitive function. (3) Selenium deficiency is unusual, but has been reported in parts of China where the local diet is devoid of selenium; the deficiency also occurs in individuals maintained on total parenteral nutrition without trace minerals. Clinical features of selenium deficiency are cardiomyopathy and skeletal muscle dysfunction. (4) Zinc deficiency causes growth retardation in children, hypogonadism, oligospermia, alopecia, dysgeusia (impaired taste), immune dysfunction, night blindness, impaired wound healing, and skin lesions. Infants with an inherited defect in zinc absorption develop a severe deficiency state known as acrodermatitis enteropathica.

Vitamins are necessary for energy production, immune function, blood clotting and other functions. These micronutrients include (fat soluble): (1) Vitamin A, that is necessary for proper vision and organ function; (2) Vitamin D, that promotes proper immune function and assists in calcium absorption and bone growth; (3) Vitamin E, that assists immune function and acts as an antioxidant that protects cells from damage; (4) Vitamin K, that is required for blood clotting and proper bone development, and water soluble vitamins: (1) Vitamin B1 (thiamine), that helps convert nutrients into energy; (2) Vitamin B2 (riboflavin), that is necessary for energy production, cell function and fat metabolism; (3) Vitamin B3 (niacin), that drives the production of energy from food; (4) Vitamin B5 (pantothenic acid), that is necessary for fatty acid synthesis; (5) Vitamin B6 (pyridoxine), that helps your body release sugar from stored carbohydrates for energy and create red blood cells; (6) Vitamin B7 (biotin), that plays a role in the metabolism of fatty acids, amino acids and glucose; (7) Vitamin B9 (folate), that is required for proper cell division; (8) Vitamin B12 (cobalamin), that is necessary for red blood cell formation and proper nervous system and brain function; (8) Vitamin C (ascorbic acid), that Is required for the creation of neurotransmitters and collagen, the main protein in your skin.

The purpose of the current Special Issue is to further expand and add research knowledge on the vital role that dietary micronutrients hold in various physiological and metabolic pathways. In addition, to add more knowledge in regards to the relationship between dietary micronutrients bioavailability, the microbiome and bioactive compounds.

Dr. Elad Tako

Guest Editor