Supplemental Iron
Posted: Sat Feb 25, 2017 7:37 pm
Since the use of supplemental iron has been a frequent topic of discussion lately, I thought I should provide a bit of background information on the use of these pills. Please bear with me if the discussion gets a bit too technical (alright, if the chemistry gets a lot too technical), and just jump over those parts.
There are basically two different approaches used for iron supplementation, iron sulfate and iron bisglycinate. Both are generally sold as pills that deliver a total of 28 to 65mg of iron, although there may be a different number that provides the mg total of iron sulfate or iron bisglycinate per pill in addition to the amount of actual iron. The difference in the numbers is the amount of sulfate or bisglycinate in each pill.
Iron Sulfate - Iron sulfate pills are generally less expensive than iron bisglycinate. These pills should be taken on an empty stomach and should ALWAYS be taken with either a vitamin C pill or a glass of orange juice. For individuals who have a sensitive stomach, iron sulfate can cause discomfort. This is the reason why iron bisglycinate pills are often marketed as "gentle iron".
When you take an iron sulfate pill, it dissolves in the stomach. Once dissolved, it forms free iron and free sulfate. As the stomach contents enter the intestinal tract, they are exposed to the colony of bacteria that we all carry. This colony contains a variety of types of bacteria and in about 50% of us there is a type of bacteria that is able to use the sulfate ions from the pill (and probably even our last meal as well) as a source of nutrient. As these bacteria do so, they release small quantities of hydrogen sulfide, the chemical responsible for the rotten egg smell (and many other sour smelling gases). This is important because the iron from the pill can react with the hydrogen sulfide to form iron sulfide, a chemical that cannot be adsorbed by the intestines. Any iron sulfide that is formed will pass out of the intestinal tract and will have been wasted. This iron sulfide (which is black) is the reason why a side effect of taking iron sulfate can be black stools.
If any of the sulfate eating bacteria are present and are "fed" with a dose of sulfate from the pill, their temporary feeding frenzy can result in intestinal discomfort and bloating from the gas they produce and the temporary upset in the balance with our our more friendly bacteria.
However, if the iron sulfate pill was taken with orange juice or a vitamin C pill, a second reaction occurs in the stomach prior to entry into the intestines. The dissolved iron reacts with the citric acid in the orange juice or the ascorbic acid of the vitamin C to form a chelated iron compound. This chelated form of iron is still dissolved in the stomach fluids, but is not able to react with the hydrogen sulfide in the intestines. All of the chelated iron is therefore available for adsorption into the blood stream and only minimal amounts end up being lost as iron sulfide.
Iron bisglycinate - Iron bisglycinate is a form of iron where the iron is already chelated with glycine, an amino acid. Since the iron is already chelated, it is not necessary to take iron bisglycinate pills with orange juice or a vitamin C pill. These pills are also easier on the stomach because they do not contain the sulfate that is needed by the sulfate eating bacteria that can cause intestinal distress.
Finally, neither form of iron should be taken with milk or heartburn relief products that contain calcium carbonate. Both of these will neutralize the acidity of the stomach contents, which can dramatically reduce both the formation of the chelated iron compounds, and thereby the availability iron for absorption by the intestines.
There are basically two different approaches used for iron supplementation, iron sulfate and iron bisglycinate. Both are generally sold as pills that deliver a total of 28 to 65mg of iron, although there may be a different number that provides the mg total of iron sulfate or iron bisglycinate per pill in addition to the amount of actual iron. The difference in the numbers is the amount of sulfate or bisglycinate in each pill.
Iron Sulfate - Iron sulfate pills are generally less expensive than iron bisglycinate. These pills should be taken on an empty stomach and should ALWAYS be taken with either a vitamin C pill or a glass of orange juice. For individuals who have a sensitive stomach, iron sulfate can cause discomfort. This is the reason why iron bisglycinate pills are often marketed as "gentle iron".
When you take an iron sulfate pill, it dissolves in the stomach. Once dissolved, it forms free iron and free sulfate. As the stomach contents enter the intestinal tract, they are exposed to the colony of bacteria that we all carry. This colony contains a variety of types of bacteria and in about 50% of us there is a type of bacteria that is able to use the sulfate ions from the pill (and probably even our last meal as well) as a source of nutrient. As these bacteria do so, they release small quantities of hydrogen sulfide, the chemical responsible for the rotten egg smell (and many other sour smelling gases). This is important because the iron from the pill can react with the hydrogen sulfide to form iron sulfide, a chemical that cannot be adsorbed by the intestines. Any iron sulfide that is formed will pass out of the intestinal tract and will have been wasted. This iron sulfide (which is black) is the reason why a side effect of taking iron sulfate can be black stools.
If any of the sulfate eating bacteria are present and are "fed" with a dose of sulfate from the pill, their temporary feeding frenzy can result in intestinal discomfort and bloating from the gas they produce and the temporary upset in the balance with our our more friendly bacteria.
However, if the iron sulfate pill was taken with orange juice or a vitamin C pill, a second reaction occurs in the stomach prior to entry into the intestines. The dissolved iron reacts with the citric acid in the orange juice or the ascorbic acid of the vitamin C to form a chelated iron compound. This chelated form of iron is still dissolved in the stomach fluids, but is not able to react with the hydrogen sulfide in the intestines. All of the chelated iron is therefore available for adsorption into the blood stream and only minimal amounts end up being lost as iron sulfide.
Iron bisglycinate - Iron bisglycinate is a form of iron where the iron is already chelated with glycine, an amino acid. Since the iron is already chelated, it is not necessary to take iron bisglycinate pills with orange juice or a vitamin C pill. These pills are also easier on the stomach because they do not contain the sulfate that is needed by the sulfate eating bacteria that can cause intestinal distress.
Finally, neither form of iron should be taken with milk or heartburn relief products that contain calcium carbonate. Both of these will neutralize the acidity of the stomach contents, which can dramatically reduce both the formation of the chelated iron compounds, and thereby the availability iron for absorption by the intestines.