Essential minerals are nutrients necessary for various aspects of human health. Our body cannot make them, therefore we need to get sufficient amounts through our diets every day for optimum health. The functions of individual minerals are many and varied, from building bones and tissue, to regulating protein synthesis, muscle contraction, nerve impulses, hormone levels, metabolism, blood pressure, digestion, and even the absorption of other nutrients – the list goes on.
Although they are only required in small amounts, measured in milligrams or micrograms, every one of these minerals is essential to maintaining a healthy body. It may surprise you to know that the two most common minerals in the human body are calcium and phosphorus.
We have separated the essential minerals into two groups: ‘macro’ (more than 100mg/day) and ‘micro’ (less than 100mg/day). These minerals need to be balanced in the body. Both macro and micro minerals can be a problem if you get too much of them. For example, too much copper can suppress zinc absorption, and vice versa. Too much calcium can inhibit iron absorption, and too much iron can cause serious health problems.
Note: We list the recommended daily intake (RDI) for adults below each mineral, but this is just an approximate range, so please don’t use this as a guide to supplementation. Daily needs vary depending on age, gender, and for pregnant and breastfeeding women. Where the RDI is not known, we have listed the known upper tolerable limit.
Essential minerals (macro – more than 100mg per day)
One of the most important minerals for building bones and teeth. It’s also present in the blood, to help with certain metabolic functions. It is also essential for the healthy functioning of the heart.
Calcium is present in dark leafy greens, kelp, figs, sardines, salmon, oysters, hazelnuts, yogurt, cheese and other milk products.
RDI adults: 1000-1300mg/day.
Is essential for healthy sleep and nervous system, muscle relaxation and contraction, mood, energy, blood pressure, bone health and stress management.
Magnesium rich foods include dark leafy greens, pumpkin seeds, dark chocolate, whole grains, especially brown rice and quinoa, sesame seeds, almonds, yoghurt, black beans, avocados, bananas, salmon.
RDI adults: 310-420mg/day.
Helps to balance fluids and electrolytes, and plays a signaling role in our nervous system. It’s also essential for cardiovascular health and muscle contraction.
Sodium is found in many meats and vegetables, as well as iodised table salt.
RDI adults: 920-2300mg/day.
Is also responsible for helping balance fluids. It’s especially important for nerve impulses, muscle contraction and healthy blood pressure.
Potassium is found in potatoes, tomatoes, avocados, oranges, bananas, cod, flounder, salmon, chicken and other meats.
RDI adults: 2800-3800mg/day.
Phosphorus helps build strong bones and teeth.
Found in eggs, dairy, fish, meat, poultry, legumes and nuts.
RDI adults: 1000mg/day.
Is essential for building proteins.
It is found in red meat, poultry, fish, eggs, dairy, nuts, legumes, garlic, onions, cabbage.
RDI adults 800-900mg/day.
Plays a role in balancing fluids, and digestive stomach acids.
Foods include tomatoes, lettuce, seaweed, rye, olives, dairy and celery.
RDI adults: 1800-2300mg/day.
Essential minerals (trace – less than 100mg per day)
Is important for helping to maintain healthy blood sugar levels and weight. It enhances the action of insulin and helps the body turn carbs, proteins and fats into energy. It’s also important for eye health, helps with the absorption of calcium.
Chromium can be found in brewer’s yeast, oats, mushrooms, asparagus, whole grains, organ meats, nuts and prunes.
RDI adults: 21-45mcg/day.
Is an essential component of blood cells, carrying oxygen throughout the body. It is important for immunity and thyroid function, collagen synthesis and energy production. Deficiency can lead to fatigue, headaches, anxiety and hair loss. Too much iron can cause problems, though, for the immune system, cell regeneration and heart health.
Iron absorption can be blocked by calcium, magnesium, manganese and zinc, so it’s important to get the balance of minerals right.
Iron rich foods include peas and beans, nuts and seeds, whole grains, lean red meat, shellfish, poultry, fish, liver and other organ meat.
RDI adults: 8-27mg/day.
Is only needed in small amounts, but has many important functions in the body, including protein production. Deficiency can result in poor wound healing, loss of appetite, altered sense of taste and smell, and reduced immunity. It’s also important for healthy reproductive system, vision, growth and blood clotting.
Foods containing zinc include black-eyed peas, pinto beans, soybeans, lima beans, whole grains, pumpkin, mushrooms, cooked greens, sesame seeds and sunflower seeds.
RDI adults: 8-14mg/day.
Is involved in the production of red blood cells, supports immunity, nervous system, liver and skin health.
Foods include lentils, soybeans, mushrooms, potatoes, tomatoes, sweet potatoes and organ meats.
RDI adults: 900-1300mcg/day.
Is necessary for the production of sex hormones, enzyme reactions, healthy bones and cartilage, and blood clotting. It’s essential for healthy brain, thyroid and nervous system.
Manganese is found in pineapples, wheat germ, nuts, seeds, whole grains and legumes.
RDI adults: 1800-2600mcg/day.
Is essential for a healthy thyroid, and deficiency can lead to hypothyroidism, abnormal weight gain and chronic fatigue. Selenium helps regulate blood pressure, and works as an antioxidant to support the immune system. Deficiency can also affect healthy ovulation and fertility and successful pregnancy. Another role of selenium is reducing toxicity caused by heavy metals.
Foods include brazil nuts, eggs, liver, tuna and poultry, but local New Zealand produce may contain less, because our soil lacks selenium.
RDI adults: 60-75mcg/day.
Is essential for regulating thyroid hormones, effecting mood, metabolism, weight management, healthy ovulation. It is important to get enough during pregnancy to ensure normal brain development.
Iodine is found in fish, seaweed and eggs.
Is important for cellular energy, a healthy nervous system, and kidney function. Excess molybdenum can cause copper retention.
Food sources include legumes, whole grains and nuts.
RDI adults: 45-50mcg/day.
Is needed for strong tooth enamel, bones and tissue.
Sources include fluoridated water, tea, canned salmon (with bones). It’s also included in some toothpastes, to strengthen tooth enamel.
RDI adults: 3-4mg/day.
Has more recently become recognised as an essential mineral, helping to metabolise calcium and magnesium, and to regulate certain hormones.
Sources include some nuts, beans, soy and prunes.
RDI adults: not known; upper tolerable limit: 20mg/day.
Is required for building bones, tendons, blood vessels and cartilage. It is a component of collagen, nails and hair, may help with metabolism of vitamin D, calcium and magnesium.
It’s found in most whole grains, fresh fruit and vegetables.
RDI adults: 9-14mg (not known for pregnant and breastfeeding women).
Is a component of vitamin B12. It plays a part in red blood cell production, regulation of certain enzymes and healthy nervous system. It is also part of the meninges (the protective layer around your brain).
It is found in foods that contain B12, such as fish, red meat, dairy and liver. The recommended daily intake for cobalt is very, very low, but if you are getting enough B12 this should cover it.
RDI adults: 0.006-0.008mcg/day.