system
Given the following post, respond as if you're commenting on Reddit:
human
[Man of Steel]How did Clark's parents hide his powers in his youth

Throughout childhood, you have to get several check ups done, especially in your school years. In high school, you have to get multiple jabs done. One was for tetanus IIRC.  Obviously any needle would break on Clark's skin. There are also blood tests you have to take as a child.

How did they get by without arising suspicion from schools and etc.
gpt
*Required* vaccinations are a fairly new thing, and even today many places have exemptions for religious or medical reasons. They could tell the state that their child is a Jehovah's Witness with an allergy to mercury and they'd be fine.

His powers also developed over time. Super Girl was bathed in yellow solar energy for her entire trip to Earth, and hit the ground with her powers. Kal El wasn't, which is fortunate: a toddler with the ability to fly and rip steel with his bare hands would be ... difficult to contend with.

The Kents knew he was an alien, and kept a pretty close eye on on his development, mostly because they feared that the government would come and take him away. As he matured and his powers began to reveal themselves, they taught him to 1. not kill anybody and 2. hide what he was capable of.