Copper

Copper is an essential trace mineral which the body needs for a wide range of everyday functions. It's essential for normal growth and development of babies and children, it's a vital component of many enzymes which have a role in some of the body's most important chemical processes, particularly the formation of healthy blood cells and the building of strong bones. You also need it for normal nerve development and function, the creation of melanin – the pigment that colours skin and hair - and most importantly of all copper is involved in the enzymes that trigger the conversion of food into energy.

Another major function of copper is that it is one of the stepping stones in the complex process through which the body creates a group of chemicals called phospholipids. These important substances are part of the system which moves fat around the bloodstream and are eventually formed into the structure of individual cells. There is a rich concentration of phospholipids in all nervous tissue where they form part of the myelin sheath which surrounds and protects every nerve. This layer works like an insulating cover and stops the electric impulses which travel along the nerves short-circuiting from one nerve fibre to another.

Copper is widely distributed in many different foods but refined cereals, milk, dairy products and eggs contain very little. No official recommended daily intake has been set for this mineral though you need between 1.5 and 2 mg a day which most people would get from a varied and well-balanced diet. You'll need more during pregnancy and breast feeding. In the later stages of pregnancy copper passes through the placenta and is stored in the baby's liver. This is to make sure that the child has enough copper to last until weaning and is extremely important as mother's milk does not provide enough. Cow's milk contains even less copper than breast milk and copper deficiency can occur in premature babies or those feed mainly on cow's milk. The symptoms can be diarrhoea, anaemia, bone fractures and a failure to grow and gain weight.

Anyone on a restricted diet, repeated low calorie weight loss diets, chronic bowel disease, anorexia, bulimia, or any illness which results in poor nutrient absorption may easily become deficient in copper. Alcohol or drug abuse, kidney disease, chronic diarrhoea, long periods of stress, anyone who's had surgery to remove part of the digestive tract or any of the wasting diseases can result in copper deficiency. Too much uncooked bran, large doses of vitamin C, and zinc supplements can all interfere with the absorption of this mineral, which may then lead to lowered immunity, osteoporosis and an increase in the amount of bad cholesterol in the bloodstream.

Most multivitamin and mineral pills contain small amounts of copper but you should only take it as a single supplement with professional advice as it can cause toxic side effects at quite small doses. As copper is a common constituent of many agricultural fungicides and frequently used on salad crops, you must wash all fresh produce thoroughly before eating. This is even more important for children than adults as even the supposedly safe legal limit of 2 mg of copper from fungicide residues in 100 gm of food for adults, may be hazardous to a small child – it's best to buy organic.

BEST SOURCES

There is no official RDA but you should aim to get 2 mg of copper daily.

PEANUTS
1.2 mg / 100 g
Percentage of daily requirement: 30% from average 50 g portion
Copper score: 3/10

TOFU
1.7 mg / 100 g
Percentage of daily requirement: 64% from average 75 g portion
Copper score: 6/10

LAMB'S LIVER
10 mg / 100 g
Percentage of daily requirement: 750% from average 150 g portion
Copper score: 10/10

LOBSTER
1.9 mg / 100 g
Percentage of daily requirement: 80% from average 85 g portion
Copper score: 8/10

SHRIMPS
1.92 mg / 100 g
Percentage of daily requirement: 48% from average 50 g portion
Copper score: 5/10

CASHEW NUTS
2.1 mg / 100 g
Percentage of daily requirement: 52% from average 50 g portion
Copper score: 5/10