Friday, February 23, 2024

How to take an iron supplement


Seventy-eight-year-old Mabel became anemic after being hospitalized with a bleeding ulcer. She was discharged home on medicine to heal her ulcer, plus an iron supplement. Three months later, Mabel’s blood tests showed she was still significantly low in iron.

When I asked about her iron supplement, she showed me a bottle of 300mg sustained-release capsules of ferrous gluconate. "The iron tablets they gave me from the hospital upset my stomach, so I found this one instead.”

Iron supplements have been used in medicine since ancient times. Greek physicians treated people who were pale and tired with drinking water enriched with iron. They left swords in water to rust or drank the water used by blacksmiths for cooling hot iron.

Iron is a critical part of hemoglobin, a protein that carries oxygen throughout the body. Your body needs four iron atoms to make each hemoglobin molecule, giving blood its distinctive red color. Without enough iron for hemoglobin, your blood can’t carry as much oxygen, and you’ll become pale and tired.

The most common cause of iron deficiency is blood loss. You can lose blood from a bleeding ulcer in your stomach, heavy menstrual periods, or from your intestines through ulcers, hemorrhoids, or diverticulitis. Other causes include a poor diet, gastric bypass surgery, kidney disease, pregnancy, or breastfeeding. 

We treat iron deficiency anemia with iron supplements. They provide iron for hemoglobin in your blood and help replenish iron stored in your bone marrow. Most people need 100mg to 200mg of elemental iron daily over several months to accomplish this.

The most common side effect of iron is stomach or intestinal irritation. Stomach pain, constipation, nausea, vomiting, and even diarrhea can occur. Iron can also make your stools dark and cause a metallic taste.

The three most common iron supplements are ferrous sulfate, ferrous gluconate, and ferrous fumarate. Ferrous fumarate contains 33% elemental iron, ferrous sulfate has 20% elemental iron, and ferrous gluconate has only 12% elemental iron.

Iron needs an acidic environment for the best absorption. Vitamin C (ascorbic acid) improves iron absorption by converting some of it from its less soluble ferric form to a more soluble ferrous version. A six-ounce glass of orange juice can improve iron absorption by 10%.

Enteric-coated and sustained release forms of iron dissolve in your intestine instead of your stomach. Your intestines are much less acidic than your stomach, so less iron is converted to the ferrous form, resulting in you absorbing less iron from each pill.

Take iron supplements on an empty stomach, either 30 minutes before or 2-3 hours after eating, to increase iron absorption. Unfortunately, this also increases stomach irritation.

Despite taking an iron supplement for 3 months, Mabel was still quite low in iron, so I asked her to bring her iron supplement. She had ferrous gluconate 300mg sustained release capsules instead of the ferrous sulfate 300mg tablets initially prescribed for her.

“Those tablets tore up my stomach, so I switched to these because they don't bother me," explained Mabel. Ferrous gluconate has about half the elemental iron of ferrous sulfate tablets. I suggested she take 2 capsules of the ferrous gluconate every day instead of one daily since she was taking it without stomach discomfort.

Here are 7 Tips for Taking Iron Supplements Successfully:

1.         Check the elemental iron in iron tablets when comparing iron supplements.

Ferrous gluconate 300mg has only 36mg of elemental iron, compared to 65mg in 300mg of ferrous sulfate.

2.         For the most comfort, take iron with meals. For faster results, take iron without food.

If taking your iron supplement on an empty stomach causes stomach irritation, take it with food instead of skipping doses.

3.         Avoid sustained release or enteric-coated iron supplements.

Sustained release, delayed release, and enteric-coated iron supplements cause less stomach upset but also have much less iron for your body to absorb.

4.         Start with one tablet daily.

Start with one tablet daily

 of iron supplement, either with or without a meal. Take your iron supplement more frequently only if instructed to by your doctor. Higher doses of iron are not absorbed as well.

5.         Consider cooking with cast iron skillets and pans.

Cooking with cast iron increases the iron content of your food and can treat mild iron deficiency.

6.         Add vitamin C to your diet.

One small glass of orange juice or a vitamin C supplement can improve iron absorption.

7.         Keep iron tablets out of the reach of children.

Ferrous gluconate and sulfate tablets have shiny, colorful coatings identical to chocolate M&M candies.

Dr. Louise Achey, Doctor of Pharmacy, is a 43-year veteran of pharmacology and author of Why Dogs Can’t Eat Chocolate: How Medicines Work and How YOU Can Take Them Safely. Get clear answers to your medication questions at her website and blog, Ó2023 Louise Achey



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