PlainVitamins

A form of iron

Ferrous gluconate supplements

228 iron products in the NIH label database list iron as ferrous gluconate (3% of the 8,696 iron products); their median is 9 mg of iron per serving, against 5 mg across all iron products; the 23 whose only supplement ingredient is iron list a median of 27 mg (DSLD version 9.4.0, January 2026).

How does ferrous gluconate compare with the other forms?

The median amount of iron per serving in products naming each form; the count in brackets. The amount is the iron the label gives, as printed (the Supplement Facts row normally states the element; a row named as the compound usually gives the compound's weight and is left out of these figures).

Median iron per serving by form

Iron by formFerrous fumarate18 mg (1,280)Iron bisglycinate18 mg (546)Ferrous gluconate9 mg (228)Ferrous sulfate15 mg (186)Carbonyl iron24 mg (164)Polysaccharide-iron complex29 mg (38)
Iron by formFerrous fumarate18 mg (1,280)Iron bisglycinate18 mg (546)Ferrous gluconate9 mg (228)Ferrous sulfate15 mg (186)Carbonyl iron24 mg (164)Polysaccharide-iron complex29 mg (38)
Iron by formFerrous fumarate18 mg (1,280)Iron bisglycinate18 mg (546)Ferrous gluconate9 mg (228)Ferrous sulfate15 mg (186)Carbonyl iron24 mg (164)Polysaccharide-iron complex29 mg (38)
Iron by formFerrous fumarate18 mg (1,280)Iron bisglycinate18 mg (546)Ferrous gluconate9 mg (228)Ferrous sulfate15 mg (186)Carbonyl iron24 mg (164)Polysaccharide-iron complex29 mg (38)
Iron by formFerrous fumarate18 mg (1,280)Iron bisglycinate18 mg (546)Ferrous gluconate9 mg (228)Ferrous sulfate15 mg (186)Carbonyl iron24 mg (164)Polysaccharide-iron complex29 mg (38)

Source: Supplement Facts rows and their forms, NIH ODS Dietary Supplement Label Database version 9.4.0, current labels.

Products
228159 on the market
Median iron per serving
9 mgall iron products: 5 mg
Share of iron products
3%228 of 8,696

Is the amount the iron or the whole ferrous gluconate?

A Supplement Facts row normally states the iron itself (a row like "Iron (as ferrous gluconate)"); a row named as the compound (a row like "Ferrous gluconate") usually states the compound's weight, which includes what the iron is bound to and is larger than the iron it supplies. The front of a bottle may print either. Of the 228 products here, 228 give the iron in its own row (5 of them an amount far outside what other labels list, or one their own %DV disagrees with).

The adult Tolerable Upper Intake Level for iron is 45 mg a day; it covers total intake from food, water and supplements. At the most servings their labels direct, 13 of the 223 ferrous gluconate products with a plausible amount (5.8%) give more than that.

Source: Supplement Facts rows of each product's current label, NIH ODS Dietary Supplement Label Database version 9.4.0; upper limit: Institute of Medicine Dietary Reference Intakes (2011) (what counts as plausible).

What else do these products contain?

Ingredients most often listed alongside it, with the median amount in these products and in all products
IngredientShare of these productsMedian hereMedian, all products
Vitamin C75% 120 mg100 mg
Folate75% 400 mcg400 mcg
Vitamin B674% 6 mg6 mg
Vitamin B1271% 15 mcg36 mcg
Thiamin71% 5 mg5 mg
Zinc69% 7.5 mg11 mg
Riboflavin69% 5 mg4 mg
Calcium67% 130 mg115 mg
Niacin67% 25 mg20 mg
Vitamin D66% 10 mcg15 mcg

Which products are they?

60 of the 228 (on-market products first, the newest label first), ordered by the amount of iron per serving, largest first; an amount that looks like a slip or a compound's weight comes last, marked.

Source: NIH ODS Dietary Supplement Label Database version 9.4.0; the form each label names for its row. Daily Values: the FDA's Daily Value page.

Which brands make them?

Nature's Plus (18), Mission Pharmacal CitraNatal (16), Nature's Way (8), Viva Vitamins (7), Biotics Research Corporation (7), Country Life (6), ALLMAX (6), Vitamin World (5), Drucker Labs (5), Hydroxycut (4).

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