[AnonC]

No, it won’t, but that’s only after a certain limit that’s much higher than 5000IU. Even if you spend all day in the sun, your body will stop the synthesis at a certain level (10000IU in the day is what I had read long ago, but that may be incorrect or outdated).

In other words, 5000IU is much lower than what the body would naturally produce when exposed to sunlight for long durations in a day (assuming good latitude, sunny season, lower atmospheric pollution, around noon, lighter skin tone, etc.).