Non Constipating Iron Supplements

Iron supplements can cause constipation.
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Iron is an essential mineral that can be obtained from foods and supplements. Unfortunately, some iron supplements are known for causing gut issues, like constipation. There are also non-constipating iron supplements, but iron pills that don't cause constipation tend to be much less common.

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Iron Consumption and Healthy Diet

Iron is one of several essential minerals you need to consume on a daily basis. This nutrient is used to keep cells healthy and functional, and synthesize both hormones and connective tissue. Iron also helps your body make hemoglobin and myoglobin.

According to the National Institutes of Health, adult men should consume about 8 milligrams of iron per day as their recommended daily allowance (RDA) for this nutrient. Most adult women should consume 18 milligrams of iron per day, though this number can vary.


Pregnant women need more iron than average: 27 milligrams per day. Breastfeeding women need less iron — about 9 to 10 milligrams per day. Older women (51 years of age and above) need the least amount of iron, at 8 milligrams per day.

Iron typically comes from a variety of different foods you eat. This nutrient exists naturally in both plant-based and animal sources. Several foods are also fortified with this nutrient. However, all of these types of iron aren't the same. Iron that comes from animal products like meat and seafood is called heme iron. The iron found in plant-based products and fortified foods is called non-heme iron.


If you follow a standard diet, chances are that your iron consumption is adequate. However, people who avoid animal products, like vegetarians and vegans, may not consume enough of this essential nutrient. This is because non-heme iron is not as easily absorbed by the body compared to heme iron.

If you're following a diet in which you're exclusively consuming non-heme iron, you may need to consider taking a supplement. This is because the RDA for iron is 1.8 times higher for people who consume only non-heme iron. Other people who may need to consider iron supplementation include frequent blood donors, women with heavy menstrual cycles, people with gastrointestinal problems and pregnant women.


Iron and Constipation

The vast majority of healthy adults have bowel movements that range between three times per day and three times per week. In contrast, constipation is defined as having less than three bowel movements per week. If you are constipated, you may also find that your stool is harder than average and unusually difficult to pass. You might also experience unpleasant sensations in your lower stomach, as if you can't fully empty your bowels or have some sort of blockage.

Constipation can occur in anyone. It's usually completely normal when it's irregular. However, when constipation becomes more of a regular occurrence, chances are that it's related to your diet and what you've recently ingested. Even small supplements can affect your gastrointestinal system in this way.

Iron is particularly well known for causing gastrointestinal side effects like constipation. About 14 to 18 percent of Americans take a supplement containing iron. Iron isn't only found in iron pills, but is included in most mineral-based multivitamins and prenatal vitamins.

When you take iron on its own, it's frequently sold in high doses. Large amounts of iron (45 milligrams per day or more) are particularly likely to cause constipation. However, constipation from iron supplements can even occur from lower amounts, such as what's included in mixed multivitamin supplements. According to the Mayo Clinic, even the iron in prenatal vitamins is known to cause constipation.

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Non-Constipating Iron Supplements

If you're looking for iron pills that don't cause constipation, you should first assess the dose of iron you've been taking. Constipation from iron supplements can often be reduced by simply decreasing your daily dose. Of course, this may not be feasible for some people. For example, pregnant women who are vegan or vegetarian will still need fairly high daily doses of this nutrient.

Most iron supplements are made from ferrous or ferric salts. You may need to switch the type of supplement you're taking from this type of product to an alternative one. Iron supplements that won't cause constipation include:

  • Heme iron polypeptides
  • Carbonyl iron
  • Iron amino-acid chelates
  • Polysaccharide-iron complexes

There is also one type of ferrous iron, ferrous bisglycinate, that is known to cause few gastrointestinal issues, including constipation. This type also requires less iron to be effective compared to other forms of ferrous iron, making it less likely to cause gut problems.

If you aren't able to obtain non-constipating iron supplements, there are also a variety of lifestyle changes that can help minimize constipation.

Lifestyle Changes to Decrease Constipation

According to a December 2014 study in the Journal of Pediatric Gastroenterology, Hepatology and Nutrition, a variety of different lifestyle changes can help prevent and counteract constipation.

The foods you choose to eat and drink play a major role in counteracting constipation. Apple, prune and pear juices can counteract constipation, but just increasing your fluid intake in general can help prevent this gastrointestinal issue. Incorporating more fiber into your diet can also help counteract and prevent gut issues.

Fiber can be found in a variety of foods, including whole grains, fruits and vegetables. Foods that are rich in insoluble fiber are particularly beneficial for gut health, because this type of fiber promotes regular bowel movements.

Foods that are rich in probiotics, which are healthy bacteria, can also help improve your gut health. If you're trying to use probiotics to improve your gastrointestinal issues, try to consume products with Bifidobacteria or Lactobacillus species. Different bacteria can have different effects on your gut, but some of these types of bacteria have been shown to counteract constipation.

You can also incorporate a regular exercise routine as part of your day. Exercise is known to help counteract constipation.

If you've tried all of these lifestyle changes without much success, you may need to talk with your doctor. Depending on your medical history and individual needs, she might recommend stool softeners or laxatives. It's best not to use laxatives regularly without talking to your doctor first, though. Long-term use of laxatives can be dangerous to your health.