Minerals

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Potassium

Potassium is an important bulk mineral which is found mainly inside cells especially muscles and nerves.  Significant amounts can be lost in the processing and preparing of food.

Adult Requirements and Intakes

* No EAR has been set but for both men and women the Lower Reference Nutrient Intake is 2,000 mg and the Reference Nutrient Intake is 3,500 mg and the EAR would be between these two values.

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods

Sodium

Sodium is a bulk mineral that is found mainly in the water compartment outside of cells.  Most unprocessed foods contain little; however, the addition of large amounts to food has been used since ancient times to help preserve them and many of us have grown accustomed to having an unnecessarily high intake.

Adult Requirements and Intakes

* No EAR has been set but for both men and women the Lower Reference Nutrient Intake is 575 mg and the Reference Nutrient Intake is 1,600 mg and the EAR would be between these two values.

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods

Calcium

Calcium has two roles, as a bulk mineral with 99% of the body’s content in the skeleton and teeth and the remaining 1% being involved in cell structure and metabolic activity.  Calcium is added to white flour to improve its nutrient content.  Absorption requires adequate vitamin D as well as adequate gastric acid the output of which often declines in the elderly.

Adult Requirements and Intakes

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods

*Fortified food

Phosphorus

Phosphorus is the second most abundant mineral in the body and like calcium the majority, 80%, is associated with the skeleton and the remainder is needed as a component of many biochemically important compounds including those involved in energy production.  It is so widely distributed in foods that deficiency occurs as a result of metabolic disturbance rather than dietary deficiency.

Adult Requirements and Intakes

Based upon the EAR for calcium as the recommendation is that phosphorus intake should be equivalent to that of calcium

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods

Magnesium

This bulk mineral plays a role in the structure of bone and muscle and is a cofactor for many enzymes.  In plants magnesium is at the centre of the chlorophyll molecule and thus high amounts are found in many unprocessed plant-derived foods.

Adult Requirements and Intakes

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods 

Iron

Iron is a component of the oxygen-carrying pigments haemoglobin in blood and myoglobin in muscle.  These forms of iron, which are always of animal origin, are referred to as haem-iron which, when consumed in food, is well absorbed (20-30 per cent). 
Non-haem iron is the form found in vegetarian sources, eggs, dairy foods and in that added to foods such as white flour and some breakfast cereals.  It is less well absorbed and unlike haem-iron the amount can be influenced positively or negatively by many dietary factors.
Iron absorption declines in the elderly often due to the loss of gastric acid output.

Adult Requirements and Intakes

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods

*Fortified food

Copper

Copper is a trace element that is involved in diverse biochemical roles.  Large amounts can be stored in mammalian livers and shellfish are another rich source.
The amount absorbed from foods decreases in the elderly.

Adult Requirements and Intakes

The Reference Nutrient Intake for both men and women is set at 1.2 mg

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods

Zinc

Zinc is another trace element with numerous roles as a cofactor of numerous enzymes as well as structural roles influencing the shape of proteins and genetic material.  It has no storage site in the body though the majority is found in muscle.  Like iron many factors can influence its absorption.

Adult Requirements and Intakes

Average Percentage of Intake Provided by Nutritional Supplements     

Content of Individual Foods

Manganese

Manganese is a trace element with a variety of diverse roles.   Deficiency appears to be rare.  A low manganese diet may need to be followed by those with an excess, which can occasionally result from industrial exposure, liver disease or parenteral (intravenous) feeding.

Adult Requirements and Intakes

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods

**Analysis includes one result with exceptionally high levels possibly due to industrial contamination
^ United States Department of Agriculture National Nutrient Database, Standard Release 20.
www.ars.usda.gov/Aboutus/docs.htm?docid=6300

Selenium

Selenium is a trace element with properties preventing tissue damage and aiding thyroid function and is important for animal and human nutrition.  Food content is highly variable around the world due to local variations in soil concentration.  Animal feeds may be fortified with selenium and this adds indirectly to human intake.

Adult Requirements and Intakes

No EARs are set but for both men and women the Lower Reference Nutrient Intake is 40 ug and the Reference Nutrient Intake for men is 75 ug and for women is 60 ug and thus EAR values would lie between these two.

Content of Individual Foods

^ United States Department of Agriculture National Nutrient Database, Standard Release 20.
www.ars.usda.gov/Aboutus/docs.htm?docid=6300

Iodine

Iodine is a trace element that is necessary for thyroid function and is traditionally associated with seafood.  Deficiency can develop in those living in land-locked areas and in many countries table salt and that used for commercial and institution foods is, by law, fortified with iodine in order to prevent deficiency.  In the UK only one percent of salt that is consumed is fortified and the reader should note that natural sea salt provides only a small amount of iodine.  Iodised salt is not used in the production of prepared foods in the UK.
The majority in the diet comes from dairy foods as cow’s teats are often sterilized with iodine solution and some inadvertently finds its way into the milk.  There is no legal obligation for milk to contain iodine.  A few soya-based milk substitutes are fortified with iodine but most are not.
Iodine is also a component of the colouring agent erythrosine, which is used in some sweets but this is not biologically available.

Adult Requirements and Intakes

 
No EARs are set but for both men and women the Lower Reference Nutrient Intake is 70 ug and the Reference Nutrient Intake is 140 ug and thus EAR values would be between these two.

Average Percentage of Intake Provided by Nutritional Supplements

Content of Individual Foods 

*Fortified food

Chromium

Chromium is a trace element that is required in minute amounts.  It acts as part of a complex of organic compounds that potentiate the action of insulin on blood glucose.  Astonishingly only 2% of dietary chromium is absorbed.

Adult Requirements and Intakes

Average Percentage of Intake Provided by Nutritional Supplements
Not assessed

Content of Individual Foods

None listed in UK tables.  However, good sources are considered to be wholegrain cereals, nuts, legumes and meat.

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