Next in our series A to Zinc, we look at trace minerals. Trace minerals, or microminerals, are required in far smaller amounts (less than 100 mg/day) than macrominerals. Each has a specific biochemical function in the human body. There are 17 microminerals, and arguably the most well-known and supplemented is Iron.
Iron plays a key role in the formation of hemoglobin and myoglobin, a protein which takes oxygen from hemoglobin and stores it in the tissues until it is needed. It also assists in the production of adenosine triphosphate (ATP), which is essential for cellular energy and proper cell functioning; catalase, which converts hydrogen peroxide into oxygen and water; and cytochromes, which transport electrons throughout the body. Finally, iron supports brain development and keeps the immune system strong.
Women need to consume more iron than men as they lose a lot of this important nutrient during menstruation. Men aged 19 years and older should consume 8mg of iron per day, while women aged 19 to 50 years should consume more than double this amount, at 18mg per day.
There are two types of iron found in foods, heme and non-heme. Heme iron is found in meat, poultry, seafood and fish, so heme iron is the type of iron that comes from animal proteins in our diet. Good sources of heme iron are red meat, poultry (particularly the dark meat, legs and thighs), turkey and fish. Non-heme iron is found mostly in plants. Good sources include tofu, beans and legumes, dark leafy greens such as spinach and kale, and iron-fortified cereals. Heme iron is more absorbable than non-heme iron, but there are things you can do to increase the absorption of iron. Here are some tips:
• Consume non-heme iron foods with a good source of vitamin C (orange juice, grapefruit, broccoli, tomatoes).
• Avoid drinking tea, coffee, and cola with your non-heme foods.
• Avoid consuming large amounts of calcium or dairy close to your iron-rich meals or iron supplement (heme iron or non-heme iron).
Eating too much iron is rare but you can overdose if you have regular blood transfusions, take iron supplements or suffer from hemochromatosis (a metabolic disorder which causes iron to be deposited in the body’s tissues). The symptoms of iron overdose include bronze or grey colored skin, damage to the intestinal tract, dizziness, fatigue, headaches, liver failure, loss of appetite, nausea, shortness of breath, vomiting and weight loss.
Iron deficiency is one of the most common nutrient deficiencies in the world. It can be caused by bleeding (internally or externally), certain dietary deficiencies (copper, vitamin A and vitamin C), consuming high levels of certain foods (such as caffeine and tannins), donating blood regularly, and a poor dietary intake of iron. The symptoms of not having enough iron in the body include depression, dizziness, fatigue, hair loss, headaches, hypochromic anemia (a condition where the red blood cells become paler than normal due to a reduction in hemoglobin, which causes the skin to look pale), increased infection risk, loss of stamina, microcytic anemia (a condition where the red blood cells become smaller than normal), reduced concentration, and weakness.
In cases where diet does not meet the body's iron requirements, a supplement may be necessary. There are many types of iron on the market but two of the most common are ferrous sulfate and ferrous glucanate. Ferrous gluconate
has more elemental iron (readily available iron) than ferrous sulfate and can be easier on the digestive system. Please consult with your doctor before taking iron supplements.
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