Three of them complained of vomiting and restlessness after consuming the tablets, a spokesman of the Haryana Health Department said.
He said one of them was admitted to a health facility in Gurgaon and two to PGIMER Rohtak for treatment.
Last week, nearly 1300 children fell sick after they were administered the tablets as part of the Weekly Iron and Folic Acid Supplementation (WIFS) programme, the spokesman said.
The health officials had said they had only minor side effects and there was no cause for worry.
After incidents of children falling sick, the dosage of tablets to be given to students in schools was adjusted, the spokesman said.