Iron (Fe) is an essential trace mineral. Unlike other nutrients, iron requirement cannot be solely met by the diet¹ because of its low bioavailability. Iron from the diet have two forms, the heme and non-heme iron².

Iron is needed for oxygen transport, muscle activity, mitochondrial function, and DNA synthesis³. It is an essential component of hemoglobin and myoglobin – oxygen carriers and transporters in the body. Furthermore, iron facilitates the transfer of electrons in the respiratory chain; hence, plays a role in ATP synthesis⁴.

Signs and Symptoms of Deficiency or Toxicity

Iron deficiency is prevalent both in developed and developing countries. Iron depletion occurs in several stages. During the early stage, iron stores are depleted but functional iron supply is not compromised. As the deficiency progresses, functional iron stores also begin to be depleted. Finally, iron-deficiency anemia (IDA) ensues when iron is no longer able to support normal red blood cell formation due to the lack of iron⁵. Iron deficiency results from poor diet, malabsorptive disorders, and blood loss disorders².

Symptoms of iron deficiency are usually associated with anemia⁵. These includes fatigue, rapid hart rate palpitations, and rapid breathing on exertion⁵.

Iron overload from the diet does not normally happen due to its low bioavailability. However, short-term intake of 20 mg/kg iron from supplements or medications could lead to gastric upset, constipation, nausea, abdominal pain, vomiting, and faintness. In addition, an intake of 25 mg elemental iron can reduce zinc absorption².

Supplementation Guide

Below are the recommendations of the World Health Organization regarding daily iron supplementation as a public health intervention^{8, 9}.

(a) In settings where the prevalence of anemia in infants and young children is 40% or higher;
Infants and young children (6-23 months): 10-12.5mg elemental iron thru drops/syrups on a daily basis, three consecutive months in a year

(b) In settings where the prevalence of anemia in infants and young children is 40% or higher;
Preschool-age children (24-59 months): 30 mg elemental iron thru drops/syrups/tablets on a daily basis, three consecutive months in a year

(c) Where the prevalence of anemia in infants and young children is 40% or higher;
School-age children (5-12 y.o.): 3-60 mg elemental iron thru tablets or capsules daily, three consecutive months in a year.

(d) Where the prevalence of anemia in menstruating adult women and adolescent girls is 40% or higher;
Menstruating adult women and adolescent girls (non-pregnant females in the reproductive age group): 30-60 mg elemental iron thru tablets, daily, 3 consecutive months in a year.

Following are WHO recommendations for pregnant women¹

(e) Where the prevalence of anemia in menstruating adult women and adolescent girls is 40% or higher;
Menstruating adult women and adolescent girls (non-pregnant females in the reproductive age group): 30-60 mg elemental iron thru tablets, daily, 3 consecutive months in a year.

(f) When the prevalence of anemia in pregnancy is < 40%: 60 mg iron + 400 mcg folic acid daily for 6 months in pregnancy

(g) When the prevalence of anemia in pregnancy is 40% or more: 60 mg iron + 400 mcg folic acid daily for 6 months during pregnancy, and continuing to 3 months postpartum

Below are the upper limits for iron intake¹.

• For infants, 0-11 months:50 mg
• For children
  • 1-13 y.o.: 40 mg
  • 14-18 y.o.: 45 mg
• For adults, 19 years and older: 45 mg
• For pregnant/lactating: 45 mg

Iron can be affected by medications such as antacids¹⁰. Levedopa and levothyoxine reduce the absorption of the drug while proton inhibitors reduce iron absorption².