<unk> s, also known as<unk>  salts and<unk>  pills, are a number of<unk>  formulations used to treat and prevent<unk>  deficiency including<unk>  deficiency anemia. For prevention they are only recommended in those with poor absorption, heavy menstrual periods, pregnancy, hemodialysis, or a diet low in<unk> . Prevention may also be used in low birth weight babies. They are taken by mouth, injection into a vein, or injection into a muscle. While benefits may be seen in days, up to two months may be required until<unk>  levels return to normal. Common side effects include constipation, abdominal pain, dark stools, and diarrhea. Other side effects, which may occur with excessive use, include<unk>  overload and<unk>  toxicity. Ferrous salts used as supplements by mouth include ferrous fumarate, ferrous gluconate, ferrous succinate, and ferrous sulfate. Injectable forms include<unk>  dextran and<unk>  sucrose. They work by providing the<unk>  needed for making red blood cells.<unk>  pills have been used medically since at least 1681, with an easy-to-use formulation being created in 1832. It is on the World Health Organization's List of Essential Medicines. Ferrous salts are available as a generic medication and over the counter. Slow release formulations, while available, are not recommended. In 2017, ferrous sulfate was the 92nd most commonly prescribed medication in the United States, with more than eight million prescriptions.
Iron supplement
Iron preparation
Protein supplement
Phosphate supplement
Calcium supplement
Deferoxamine
Electrocution
Zinc sulfate 