The folic acid (iron) tablets were given to them as part of Haryana Health Department's supplementation programme to combat anaemia, sources said.
The students were rushed to Gurgaon civil hospital after they complained of giddiness and pain in abdomen, they said.
Around 70 students from Sohna and 15 each from Pataudi and Sikenderpur were brought to the hospital, a source said, adding most of them were discharged after treatment.