Is a prescription for vitamin d deficiency temporary? Can the body correct itself after taking vitamin d (50, 000 iu weekly) for several months

Vit D. 20 minutes of sunshine a day is important for vit d absorbtion. Need calcium as well. Your doctor needs to check you vit d level to decide what is the proper dose of vit d. Most people need less than you but this is individualized. We dont know your age, or personal health profile. Many of the decisions are based on your health profile.
Mostly, yes. Most cases of vitamin deficiency respond very well to initial high dose vit d and once optimum levels are reached (easily checked by lab level), then maintenance by usual rda is adequate.