Iron, Iodine And Zinc – The Micro Minerals

There are some minerals which are needed in the diet in amounts less than100mg/day. These are referred to as trace elements. These minerals include Iron, Zinc, Iodine, Manganese, Selenium and Copper.

Iron

Why do we need iron?
Iron is a mineral that plays a crucial role in many different body functions. It helps to carry oxygen throughout the body in the form of haemoglobin (component of red blood cells that transport oxygen to tissues) and myoglobin (protein that carries oxygen to muscle) and fight off infection. It is an integral part of many proteins and enzymes and helps in energy metabolism.

How much iron do you need?
Some groups of people need more iron than the other. ICMR recommends 9 mg of iron per day for children from 1 to 3 years of age, 13 mg for children from 4 to 6 years of age, 16 mg for 7-9 years of age. The increase in iron requirements with age in children is because of increased iron requirements for skeletal growth, lean body mass and blood expansion in the body.

For adolescent boys from 10 to 17 years of age, 21-28 mg of iron per day and for adolescent girls for the same age group, 26-27 mg of iron is recommended. In adolescent age, additional iron is required for the growth spurt (blood volume expansion, increase in haemoglobin concentration and muscle mass) and in females, extra iron is also needed to account for menstrual losses.

For adult males, 21 mg of iron and for adult females, 17 mg of iron is recommended.

Pregnant woman are recommended to have 35 mg of iron. Their iron needs increase as more iron is needed considering iron needs of foetus’ growth, expansion of mother’s tissue and blood loss. Lactating mothers are recommended to have 21 mg of iron per day considering requirement of the mother and to make up for the iron lost in breast milk.

What are some good iron sources?

There are two types of iron in food: heme iron and non-heme iron. Heme iron is absorbed more easily by the body than non-heme iron, and is found in meat, fish and poultry. Non-heme iron is found in enriched and whole grains like bajra,ragi, nuts like raisins, green leafy vegetables like spinach, amaranth, legumes, jaggery, rice flakes etc.

Iron content of food sources by Nutritive Value of Indian Foods, NIN

Food

Iron (mg)/100g

Non-Heme Sources

Spinach

3.4

Bathua Leaves

4.2

Rice flakes

20

Soyabean

10.4

Lentil

7.58

Raisins

7.7

Jaggery

2.64

Heme-Sources

Eggs

2.1

Beef, meal

18.8

Mutton Muscle

2.5

Liver, sheep

6.3

Deficiency of iron causes anaemia which can cause you to feel tired and irritable, and it can affect your ability to concentrate. Other common symptoms are blood in the stools, brittle nails, decreased appetite, headache, weakness, pale skin color (pallor), shortness of breath, sore tongue etc.

Fun Facts:

  • Eating foods that are high in vitamin C, such as oranges (and other citrus fruits), strawberries, tomatoes, broccoli, peppers and kiwis, helps your body absorb iron if eaten during the same meal! Vitamin C and meat protein (eg in the form of beef, fish or poultry) improve the absorption of non-heme iron
  • Tannins (found in tea) may decrease absorption of non-heme iron. So, it’s best to avoid drinking tea or coffee with the meals

Iodine:
Iodine is an essential trace element that our bodies need for normal growth and development. It is mainly found in the ocean and the soil – although in quite small concentrations. We get our iodine from the plants and animals we eat. How much depends on the concentration of iodine in the soils in which they were grown. The most potent source of iodine in our diet is ocean fish and other seafood.

What Does Iodine Do?

  • Iodine is essential nutrient and is required for regulating metabolism through its role in thyroid function. Thyroid hormones play a vital role in regulating metabolic processes such as growth and energy expenditure
  • Iodine is essential for the normal development of the brain and nervous system especially during pregnancy and the first three years of life. Studies have shown that children with low iodine levels may have their hearing, coordination and alertness affected. Iodine is also critical for normal development of babies in the womb. Pregnant women, or women who plan to become pregnant, should ensure their iodine intake is satisfactory

Which Foods Are Sources Of Iodine?

  • Salt water fish (shellfish, coal fish, tuna, salmon and cod)
  • Iodized salt and products processed with it

How Much IodineDo You Need?

ICMR recommends 0.07-0.38 mg of iodine for first five years, 0.1-0.14 mg of iron for children from 6 to 12 years. 0.11-0.12 mg of iodine is recommended for normal adult (males and females) and 0.247 mg of iodine for pregnant and lactating mothers. The high RDA’s for iodine in childhood and pregnancy are there because of essential role of iodine in brain development in first three years and in pregnancy. Consequences of Iodine deficiency in these vulnerable periods of life are irreversible.

Zinc:

Zinc is an essential mineral for human health. It is contained predominantly in the bones, skin and hair (70%) with almost the entire remainder occurring in liver, kidney and muscle. Only traces are found in blood.

Why Do You Need Zinc?

Many body processes depend on zinc like enzyme, hormone and vitamin A activity. Zinc helps in activity of the immune system and storage and release of insulin. Zinc is important for proper senses of taste and smell as well.

Which Foods Are The Sources Of Zinc?

Seafood (eg oysters and crab), red meat, chicken (the dark meat of a chicken has more Zn than the light meat), eggs and dairy products, leafy green vegetables, whole grain products, legumes (eg beans & peanuts) and nuts are good sources of zinc.

Zinc in animal foods is better absorbed than that in plant foods because plant foods are high in substances (eg tannins, phytic acid, oxalic acids) that bind zinc.

How Much Zinc Do You Need?

ICMR recommends zinc intake of 5-9 mg for children from 1 to 12 years of age. 11 to 12 mg of iodine is recommended for 13 to 17 years of age. 10-12 mg of zinc is recommended for males and females. RDA for pregnant and lactating mothers is 12 mg of zinc per day.