Minerals are inorganic elements required by the human body to support numerous physiological processes, from nerve signaling to bone formation. These nutrients are categorized by the quantity needed for optimal health. Macrominerals, like calcium and potassium, are required in amounts greater than 100 milligrams per day. Trace minerals are needed in far smaller quantities. The number “72” often appears in the supplement industry regarding trace minerals. This article clarifies the scientific classification of trace minerals and addresses the context of the “72” claim to determine which elements are essential for human nutrition.
Defining Trace Minerals in Nutrition
Trace minerals, sometimes called microminerals, are defined by the low daily intake required by the body, typically less than 100 milligrams per day. Despite these minute requirements, they serve as cofactors necessary for countless enzyme systems that regulate metabolism, growth, and development.
The scientific community recognizes a specific set of minerals as essential trace elements for human health. An element is considered essential if a deficiency consistently causes a physiological impairment that can be reversed by adequate intake of that specific element.
There are nine universally recognized essential trace minerals that must be obtained through the diet: iron, zinc, copper, iodine, selenium, manganese, molybdenum, chromium, and fluoride. The required daily allowance (RDA) for most of these minerals falls between 0.2 and 15 milligrams. This highlights the small but precise amounts necessary for proper function, as the range between insufficient intake and potentially harmful excess intake is narrow.
The Context of the “72” Number
The frequent mention of “72 trace minerals” largely originates from the marketing of mineral supplements derived from specific geological sources. These products are typically sourced from mineral-rich materials, such as concentrated water from the Great Salt Lake or ancient seabed deposits. These natural sources contain virtually every element found in the earth’s crust, which can number over 70, including elements like gold, silver, and vanadium. The claim of “72” reflects the elemental composition of the raw source material, not established human nutritional requirements.
The elements included in this larger number, beyond the nine essential trace minerals, are often referred to as ultra-trace elements. Many of these lack an established Recommended Daily Allowance (RDA) because nutritional science has not demonstrated a clear biological function in the human body. While the presence of ultra-trace elements like germanium or boron is verifiable, their necessity for human health remains unproven. The nutritional focus is on elements with established physiological roles.
Key Roles of Essential Trace Minerals
The nine essential trace minerals perform highly specialized and non-interchangeable functions at the cellular level. Iron is integral to oxygen transport, forming a component of hemoglobin in red blood cells that carries oxygen from the lungs to tissues. It also participates in cellular energy metabolism as part of electron transport chain enzymes.
Zinc is important for immune system function and is a cofactor for over 300 enzymes involved in DNA synthesis, cell division, and wound healing. Iodine is required exclusively for the synthesis of thyroid hormones (T4 and T3), which regulate the body’s overall metabolic rate and are needed for proper growth and neurological development.
Selenium acts primarily as an antioxidant, incorporated into selenoproteins like glutathione peroxidase, which helps protect cells from oxidative damage. Manganese is involved in bone formation and the metabolism of carbohydrates, proteins, and fats. Chromium works closely with insulin to help regulate blood glucose levels.
Dietary Intake and Sources
The body cannot manufacture trace minerals, so they must be supplied through the diet. A varied diet that includes whole grains, legumes, meats, and produce is the most effective way to acquire sufficient quantities of the essential trace minerals. The mineral content of plant-based foods depends on the quality and composition of the soil in which they are grown, meaning soil depletion can affect the concentration of minerals in the harvested food.
When considering supplementation, bioavailability is important, referring to the fraction of an ingested mineral that the body actually absorbs and uses. Certain compounds in whole foods, such as phytic acid in grains and legumes, can bind to minerals like iron and zinc, potentially reducing absorption. Obtaining essential trace minerals through whole foods generally ensures a balanced intake and avoids mineral-mineral interactions that could interfere with absorption.