What foods are high in trace minerals?

The body requires a number of minerals in order to maintain its proper functioning.

The minerals are used for a variety of physiological processes such as building blood and bone, making hormones, regulating heartbeat, and more.

There are two types of minerals.

Macrominerals are needed in large amounts. Trace minerals are needed in very small amounts.

The macrominerals are calcium, phosphorus, magnesium, sodium, potassium, chloride, and sulfur.

The trace minerals are iron, manganese, copper, iodine, zinc, cobalt, fluoride, and selenium.

Calcium

Calcium is the most abundant mineral in the body. It is used structurally, to build bones and teeth, and also as a messenger in cell signaling.

In addition to forming the primary structure of our body, the bones also serve as a calcium reserve in case of dietary deficiency.

Dietary calcium is therefore extremely important to prevent loss of bone. Calcium balance is maintained by parathyroid hormone.

The US recommended daily allowance of calcium is 1000-1200 mg/day for adults.

Calcium Rich Foods - Image Credit: Shutterstock

Phosphorus

Phosphorus forms a part of the bones in the form of the mineral hydroxyapatite. It is also used in cell membranes, and is part of the energy molecules, adenosine triphosphate (ATP) and adenosine diphosphate (ADP). DNA and RNA also contain phosphate.

The RDA of phosphorus is 700 mg for adults. Phosphorus is abundant in most food sources.

Magnesium

Magnesium is widely used by the body for metabolic processes. Some of its main functions include energy production, synthesis of biomolecules, and as a structural component of cell membranes and chromosomes.

Magnesium is also used in ion transport, cell signaling, and cell migration. The RDA for magnesium is 400-420 mg for men and 310-320 mg for women.

Sodium and chloride are critical life-sustaining minerals. Sodium chloride (salt) is a required part of the diet. With potassium, sodium and chloride maintain charge gradients across cell walls.

Sodium helps to maintain proper blood volume and blood pressure. Most adults require between 1.5 and 3.8 grams of sodium chloride per day.

In addition to acting as an electrolyte in the body, potassium also functions as a cofactor for a number of enzymes. Low potassium levels can be dangerous, resulting in fatigue, muscle cramps, and abdominal pain. Adults need about 4.7 grams of potassium per day.

Sulfur

Sulfur is an important component of two amino acids, cysteine and methionine, that are used in most proteins of the body.

Because sulfur is abundant in nature, it is not usually classed as a required nutrient in the diet.

Iron

Iron is used in red blood cells to carry oxygen to the tissues, and is also a critical component of many metabolic proteins and enzymes.

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Iron is found in the body in the form of heme iron and non-heme iron.

Heme iron is bound within a ring-like molecule called porphyrin. Heme iron is present in red blood cells.

Non-heme iron such as iron-sulfur cluster proteins are used in energy production and other metabolic functions. The RDA of iron for men is 8 mg, for women 18 mg, and for pregnant women 27 mg.

Manganese

The functions of manganese include antioxidant activity in the mitochondria, assisting enzymes in metabolism, bone development, and wound healing.

Adequate daily intake of manganese is 2.3 mg for men and 1.8 mg for women. Deficiency of manganese can lead to osteoporosis, diabetes, and epilepsy.

Copper

Copper is a cofactor for certain enzymes involved in energy production, connective tissue formation, and iron metabolism.

Copper deficiency can be caused by poor nutrition, poor absorption, or excessive zing intake.

The US RDA of copper is 800 micrograms for adults. Copper is found in shellfish, nuts, seeds, and whole grains.

Iodine is a critical mineral in the body. It is a component of the thyroid hormone and is required for normal thyroid function.

Iodine is found naturally in seafood, dairy products, grains, eggs, and poultry.

Additionally, in the US and many other countries, salt is fortified with iodine to prevent deficiencies in the population.

Iodine deficiency can cause brain damage, mental retardation, hypothyroidism, goiter, and other health problems. The US RDA of iodine is 150 micrograms.

Zinc

Zinc plays multiple roles in the body. It is involved in many cellular metabolic processes and is used in growth and development, the immune system, neurological function, and reproduction.

It also forms a structural part of cell membranes and is a component of the zinc finger proteins, which act as transcription factors.

The US RDA for zinc is 11 mg for men and 8 mg for women.

Cobalt

Cobalt is present in the body as a part of vitamin B12, which is involved in manufacture of blood cells and nervous system function.

Fluoride

Fluoride hardens tooth enamel and stabilizes the mineral in bones. Natural sources of fluoride include tea, fish consumed with the bones, and some fruit juices.

However, the major source of dietary fluoride in the US is fluoridated drinking water.

The average fluoride intake per day in areas with fluoridated drinking water is 1.4 to 3.4 mg. In areas without fluoridated water, it is 0.3 to 1 mg per day.

Selenium

Selenium functions in the body in the form of selenoproteins, which have many metabolic functions.

The US RDA for selenium is 55 micrograms. Foods rich in selenium include Brazil nuts, tuna, oysters, pork, beef, chicken, whole wheat bread, and milk.

Deficiency of selenium does not usually result in obvious clinical illness, but may contribute to Keshan disease and Kashin-Beck disease.

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Last updated Feb 27, 2019

A healthy balanced diet containing a variety of foods should provide all the vitamins your body needs to work properly.

There are 2 types of vitamins, fat-soluble and water-soluble.

Fat-soluble vitamins

Fat-soluble vitamins are mainly found in foods that are high in natural fat - such as dairy, eggs and oily fish.

You don't need to eat these types of food every day to get enough of these vitamins. Every time you eat these foods your body stores them in your liver and body fat for future use.

Fat-soluble vitamins include:

• vitamin A
• vitamin D
• vitamin E
• vitamin K

Vitamin A

Vitamin A (also known as retinol) has several important functions, including:

• helping your immune system to fight infections
• helping your vision in dim light
• keeping your skin healthy

Good sources of vitamin A include:

• cheese
• eggs
• oily fish
• fortified low-fat spreads
• milk and yoghurt

Vitamin D

Vitamin D helps to regulate the amount of calcium and phosphate in the body, important for bone, teeth and muscle health.

Vitamin D is made by our skin from sunlight and is also found in small amounts in some foods.

Good sources of vitamin D include:

• oily fish – such as salmon, herring and mackerel
• red meat and offal - such as liver and kidney
• egg yolks
• fortified cereals, soya products and spreads

Since vitamin D is found in only a small number of foods. In Scotland everyone over the age of 5 should consider taking a supplement with vitamin D, especially over the winter. Therefore, everyone aged over one year - including pregnant and breastfeeding women - should consider taking a daily supplement containing 10 micrograms of vitamin D.

Between April and September, the majority of people aged 5 years and above will probably get enough vitamin D from sunlight when they are outdoors. They might choose not to take a vitamin D supplement during these months.

Some population groups (with very little or no sunshine exposure) will not obtain enough vitamin D from sunlight and are at greater risk of vitamin D deficiency. This includes:

• people who are seldom outdoors such as frail or housebound individuals and those who are confined indoors e.g. in institutions such as care homes
• people who habitually wear clothes that cover most of their skin while outdoors
• people from minority ethnic groups with dark skin such as those of African, African-Caribbean and South Asian origin

These people should take a daily supplement containing 10 micrograms vitamin D throughout the year.

Given the uncertainty of consistent sunshine in Scotland and the risks of exposing infants 0-6 months to the sun, it may be advisable for pregnant and lactating women to take a daily supplement throughout the year.

Staying safe in the sun

In Scotland, 10 to 15 minutes of unprotected sun exposure is safe for all. After sunscreen is correctly applied, vitamin D synthesis is blocked.

Staying in the sun for prolonged periods without the protection of sunscreen increases the risk of skin cancer.

Vitamin E

Vitamin E is a powerful antioxidant that helps to:

• repair damaged cells and protect them from free-radicals
• keep your skin and eyes healthy
• strengthen your immune system

Good sources of vitamin E include:

• plant-based oils - such as olive and rapeseed
• nuts and seeds
• cereals and cereal products

Vitamin K

Vitamin K is important for healthy bones and blood clotting, an essential part of healing.

Good sources of vitamin K include:

• green leafy vegetables – such as broccoli and spinach
• plant-based oils
• nuts and seeds
• meat
• dairy products
• soya beans

Water-soluble vitamins

Unlike fat-soluble vitamins, you need to consume water-soluble vitamins more often. Your body can't store these for future use and gets rid of any excess when you pass urine.

Water-soluble vitamins include:

• vitamin C
• B vitamins
• folic acid

They're found in:

• fruit and vegetables
• grains
• dairy foods

Being water soluble, these vitamins can be lost or destroyed through heating, dissolving or exposure to air. To keep as many of these as possible, choose to steam or grill these foods instead of boiling (unless you're making soups or stews with the liquid).

Vitamin C

Vitamin C (also known as ascorbic acid) helps to:

• protect and keep cells healthy
• maintain healthy connective tissue
• heal wounds

Vitamin C is found in a wide variety of fruit and vegetables. Good sources include:

• citrus fruit - including oranges and grapefruit
• red and green peppers
• potatoes
• strawberries, blueberries and blackberries
• green leafy vegetables - such as broccoli and brussels sprouts

Vitamin B1 (thiamin)

Thiamin is also known as vitamin B1. It helps the other B vitamins to break down and release energy from food and keep your nervous system healthy.

Thiamin is found in most types of food. Good sources include:

• meat and fish - such as pork and trout
• vegetables – such as peas, asparagus and squash
• fresh and dried fruit
• eggs
• wholegrain breads
• some fortified breakfast cereal

Vitamin B2 (riboflavin)

Riboflavin is also known as vitamin B2. It helps to keep your skin, eyes and nervous system healthy and release energy from the food you eat.

Good sources of riboflavin include:

• milk
• eggs
• fortified breakfast cereals
• rice

Vitamin B3 (niacin)

Niacin is also known as vitamin B3. It helps to release energy from the foods you eat and keep your skin and nervous system healthy.

There are 2 forms of niacin – nicotinic acid and nicotinamide – both of which are found in food.

Good sources of niacin include:

• meat
• fish
• wheat flour
• eggs
• milk

Pantothenic acid

Pantothenic acid helps to release energy from the food we eat. It's found naturally in most meats, vegetables and wholegrains, including:

• chicken and beef
• potatoes
• tomatoes and broccoli
• kidney
• eggs
• wholegrains – such as brown rice and wholemeal bread
• porridge

Vitamin B6 (pyridoxine)

Pyridoxine is also known as vitamin B6. It helps the body to:

• use and store energy from protein and carbohydrates in food
• form the substance that carries oxygen around the body (haemoglobin) in your blood

Good sources of vitamin B6 include:

• lean meat - such as chicken or turkey
• fish
• whole cereals – such as oatmeal, brown rice and wholegrain bread
• eggs
• vegetables
• soya beans
• peanuts
• milk
• potatoes

Vitamin B7 (Biotin)

Biotin is also known as vitamin B7 and is only needed in small amounts. It helps your body process (metabolise) fat.

As the bacteria in your bowel make biotin, you may not need any additional biotin from your diet. However, it's still important to eat a healthy and varied diet.

Vitamin B12

Vitamin B12 helps your body:

• make red blood cells and keep the nervous system healthy
• release energy from the food we eat
• process folic acid

Good sources include:

• meat
• fish - such as salmon and cod
• shellfish
• dairy foods
• eggs
• some fortified breakfast cereals

Vitamin B12 is not found naturally in plants and grains. If you're vegan, you should consider taking a B vitamin supplement to reduce the risk of developing vitamin B12 deficiency anaemia.

Folic acid

Folic acid (also known as folate) works with vitamin B12 to form healthy red blood cells.

It can also help to reduce the risk of central nervous system defects - such as spina bifida - in unborn babies.

Good sources of folic acid include:

• broccoli
• brussels sprouts
• liver
• spinach
• asparagus
• peas
• chickpeas
• fortified breakfast cereals

If you don't have enough folic acid in your diet you're at risk of developing folate deficiency anaemia.

More about folic acid before and during pregnancy