Mineral and trace element supplements

As with vitamins, it is considered to be best to obtain our mineral requirements from food. As with vitamins, if you wish to take supplements it is best not to exceed the recommended nutrient intake or recommended daily allowances – and care must be taken regarding the combinations taken as high doses of certain minerals can affect the absorption of others. Some further information is given below about some of the minerals and trace elements that are commonly seen as supplements.

Iron

There are some groups in the population who do not obtain enough iron in the diet. The main groups at risk of low iron intake are:

• Infants and children from the age of 6 months to 2 years
• Younger adolescents (especially girls)
• Women of child-bearing age
• Pregnant women
• Vegetarians

Iron deficiency results in a type of anemia where the red blood cells are smaller and paler than usual and are less able to carry oxygen to the body tissues. Symptoms include tiredness, weakness, pale skin, breathlessness on exertion, and sometimes palpitations. People with severe iron deficiency have impaired intellectual performance, poor work capacity, and poor immune and nerve function. In children low iron status may affect learning ability and behavior.

It is preferable to obtain the necessary iron from food sources but supplements may be useful in some situations. (Babies and toddlers should obtain all the iron they need without supplements provided that appropriate milk formula are used. Consult a Health professional or dietitian for advice about appropriate formula). Iron is toxic at doses of 40 mg or more per day in adults. Care should be taken as supplements are available that contain up to 50 mg. Iron supplements may be in liquid or tablet form. Liquid supplements should be diluted well and taken through a straw (to prevent discoloration of the teeth). Iron is best taken on an empty stomach to maximize absorption, but if taken with food there is less risk of stomach upsets.

Iron supplements may cause gastrointestinal irritation, nausea, and constipation, which can be a particular problem in the elderly. Routine iron supplementation is no longer the rule in pregnancy; iron status should be monitored and supplements taken only on advice from an appropriate health professional.

Absorption of iron may be affected by various drugs, including antacids, some antibiotics, and other nutrient supplements. Calcium supplements may reduce iron absorption; large doses of iron may reduce absorption of copper and zinc, and vice versa, and iron reduces absorption of manganese. Vitamin E requirements may be increased if large doses of iron supplements are taken, and vitamin E supplements may prevent adequate blood-forming responses in people with iron deficiency anemia.

For all the above reasons it is probably best to take advice form a health professional if you are contemplating taking iron supplements. This is always advisable in the case of infants and young children.