"...all doctors should be able to diagnose and treat nutritional deficiencies."

Royal College of Physicians. Nutrition and Patients: A Doctor's Responsibility. London 2002

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Minerals

Main page | Energy & Protein | Vitamins | Minerals | Essential Fatty Acids

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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

 
Men
Women
Estimated Average Requirements mg/day
None set*
None set*
Mean Intakes mg/day – NDNS data
3371
2655

* 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

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
0.1%
0
<1%
Females
0
0
0.1%
0
<1%

Content of Individual Foods

Food Potassium content (mg) per 100g
Paprika 2340
Dried apricots 1380
Potato crisps 1060
Raisins 1020
Dried figs 970
Almonds 780
Peanuts 670
Jacket potatoes 630
Pasta, white, plain, fresh, boiled 49
Rice, brown, cooked 99
Rice, white, cooked 54
Raw spinach 500
Grilled chicken breast 460
Avocado 450
Salmon 430
Beef , rump steak, lean, grilled 430
Porridge oats 429
Pork loin chops, grilled, lean 410
Bananas 400
Tomato ketchup 350
Lamb, shoulder, lean, roast 330
Brussels sprouts 310
Blackcurrants, stewed with sugar 290
Tomatoes, raw 250
Whole meal bread 253
White bread 137
Oranges 150
Orange juice, unsweetened 150
Apples, eating, average 120

 

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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

 
Men
Women
Estimated Average Requirements mg/day
None set*
None set*
Mean Intakes mg/day – NDNS data
3320
2303

* 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

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
0.2%
0
0
Females
0
0
0
0
0

Content of Individual Foods

Food Sodium content (mg) per 100g
Tinned anchovies 3930
Bacon 1880
Ketchup 1630
Feta cheese 1440
Ham 1200
Corn flakes 1000
Crisps 800
Cheddar cheese 723
French stick 616
Tinned sardines in brine 530
Digestive biscuits 500
Whole meal bread 487
White bread 461
Tinned sardines in oil 450
Tinned tomato soup 400
Roast pork 69
Muesli no added sugar 47
Full milk 43

 

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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

 
Men
Women
Estimated Average Requirements mg/day
525
525
Mean Intakes mg/day – NDNS data
1016
809

Average Percentage of Intake Provided by Nutritional Supplements

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
1.0%
<1%
0
Females
0
0
4.0%
1%
<1%

Content of Individual Foods

Food Calcium content (mg) per 100g
Tofu 1480
Cheddar cheese 739
Sesame seeds 670
Tinned sardines 500
Feta cheese 360
Tinned anchovies 300
Dried figs 250
Almonds 240
Plain whole milk yoghurt 200
White bread* 177
Watercress 170
Semi-skimmed milk 120

*Fortified food

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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

 
Men
Women
Estimated Average Requirements mg/day
525*
525*
Mean Intakes mg/day – NDNS data
1502
1116

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

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
1.0%
0
0
Females
0
0
0.4%
0
0

Content of Individual Foods

Food Phosphorus content (mg) per 100g
Brazil nuts 590
Tinned sardines 520
Cheddar cheese 505
Bran flakes 450
Sardines, tinned, in tomato sauce 400
Muesli no added sugar 330
Grilled chicken breast 310
Instant coffee 310
Rump steak grilled 260
Whole meal bread 202
White bread 95
Eggs, whole, boiled 200
Baked cod 190
Bacon 180
Whole milk 93
Cola 30

 

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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

 
Men
Women
Estimated Average Requirements mg/day
250
200
Mean Intakes mg/day – NDNS data
311
233

Average Percentage of Intake Provided by Nutritional Supplements

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
1.5%
0
0
Females
0
0
2.0%
0
0

Content of Individual Foods 

Food Magnesium content (mg) per 100g
Brazil nuts 410
Sunflower seeds 390
Almonds 270
Porridge oats 177
Shredded wheat 130
Rye crisp bread 100
Muesli no added sugar 90
Dried figs 80
Tofu 67
Whole meal bread 66
Hummus 62
Raw spinach 54

 

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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

 
Men
Women
Age 19-50 yrs
Women
Age > 50 yrs
Estimated Average Requirements mg/day
6.7
11.4
6.7
Mean Intakes mg/day – NDNS data
14
11.0
12.3

Average Percentage of Intake Provided by Nutritional Supplements

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
4%
1%
6%
6%
0
Females
4%
2%
14%
3%
1%

Content of Individual Foods

Food Iron content (mg) per 100g
Thyme, dried 123.6
Curry powder 58.3
Paprika 23.6
Cockles 28.0
Calves liver 12.2
Weetabix 11.9
Lamb kidneys 11.2
Sesame seeds 10.4
Cornflakes* 7.9
Mussels 6.8
Sunflower seeds 6.4
Cashew nuts 6.2
Roast venison 5.1
Porridge oats 4.7
Dried figs 4.2
Grilled lean beef steak 3.6
Green/brown lentils 3.5
Dried apricots 3.4
Wholemeal bread 2.4
White bread* 1.6
Chicken, roasted, meat, average 0.8
Pheasant, roasted, meat only 2.2
Duck, roasted, meat only 2.7
Red wine 0.9
White wine 0.5

*Fortified food

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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

Men
Women
Estimated Average Requirements mg/day
None set
None set
Mean Intakes mg/day – NDNS data
1.48
1.07

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

Average Percentage of Intake Provided by Nutritional Supplements

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
3.5%
0
0
Females
0
0
4.0%
0
0

Content of Individual Foods

Food Copper content (mg) per 100g
Calves liver 23.86
Whelks 6.59
Sunflower seeds 2.27
Cashew nuts 2.04
Crab 1.77
Brazil nuts 1.76
Lobster 1.35
Peanuts 1.02
Squid 0.68
Tofu 0.58
Weetabix 0.54
Cheddar cheese 0.03
Stilton cheese 0.04

 

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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

 
Men
Women
Estimated Average Requirements mg/day
7.3
5.5
Mean Intakes mg/day – NDNS data
10.7
7.4

Average Percentage of Intake Provided by Nutritional Supplements     

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
4.5%
1%
0
Females
0
0
6.5%
1%
0

Content of Individual Foods

Food Zinc content (mg) per 100g
Calves liver 15.9
Whelks 12.1
Cashew nuts 5.7
Grilled lean beef steak 5.6
Crab 5.5
Pecan nuts 5.3
Brazil nuts 4.2
Cheddar cheese 4.1
Stilton cheese 2.9
Chicken liver 3.8
Lamb chops 3.6
Rye crisp bread 3.0
Prawns 2.2

 

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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

 
Men
Women
Estimated Average Requirements mg/day
None set
None set
Mean Intakes mg/day – NDNS data
3.42
2.77

Average Percentage of Intake Provided by Nutritional Supplements

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
3%
0
0
Females
0
0
3%
0
0

Content of Individual Foods

Food Manganese content (mg) per 100g
Hazelnuts 4.9
Pecan nuts 4.6
Rye crisp bread 3.5
Muesli no added sugar 2.6
Sunflower seeds 2.2
Peanuts 2.1
Whole meal bread 1.8
Almonds 1.7
Blackberries ** 1.4
Blackberries US^ 0.65
Tofu 1.2
Brown rice (boiled) 0.9
Tinned Pineapple 0.9
Fresh pineapple 0.5
Chickpeas 0.8
Blackcurrants 0.3
Tea       0.15

**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

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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

 
Men
Women
Estimated Average Requirements ug/day
None set
None set
Mean Intakes ug/day – NDNS data
Data not presented
Data not presented

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

Food Selenium content (mg) per 100g
Brazil nuts 254
Lamb kidneys 209
Crab 84
Tinned tuna 78
Squid 66
Lamb’s liver 62
Lobster 54
Tinned sardines 49
Sunflower seeds 49
Mussels 43
Cashew nuts 34
Cod/haddock 28
Prawns 23
Pork chops 18
Whole meal bread 7
White bread 6
White bread USDA^ 17.3
Lamb leg roasted UK 4
Lamb leg roasted NZ^ 4.2
Lamb leg roasted US^ 30.1
Hazelnuts 2

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

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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

 
Men
Women
Estimated Average Requirements ug/day
None set
None set
Mean Intakes ug/day – NDNS data
220
167

 
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

 
Infants
1.5 to 4.5 yrs
Children
4 to 18 yrs
Adults
19 to 64 yrs
Elderly –
Free-living
> 65 yrs
Elderly –
Institutional
> 65 yrs
Males
0
0
2.5%
0
0
Females
0
0
5%
0
0

 

Content of Individual Foods 

Food Iodine content (mg) per 100g
Haddock 260
Mackerel 170
Mussels 120
Cod 110
Plain yoghurt (whole milk) 63
Eggs 53
Salmon 44
Cow’s milk 30
Cheddar cheese 30
Prawns 30
Tinned sardines 23
Brazil nuts/peanuts 20
Beer -
Lager -
Soya milk 1
Alpro/So Good Soya milks chilled*  
Alpro soya milk unfortified  
Iodised salt* Cerebros brand 1150
Sea salt 50
Table salt 44

*Fortified food

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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

 
Men
Women
Estimated Average Requirements ug/day
None set
None set
Mean Intakes ug/day – NDNS data
Data not presented
Data not presented

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.

 

Main page | Energy & Protein | Vitamins | Minerals | Essential Fatty Acids



Copyright Dr. Alan Stewart M.B.B.S.M.R.C.P. (UK)M.F. Hom.
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