Read this hefore taking 10000 units of vitsmin D on a daily basis:
https://www.mayoclinic.org/drugs-supplements-vitamin-d/art-20363792
Safety and side effects
Taken in appropriate doses, vitamin D is generally considered safe.
However, taking too much vitamin D in the form of supplements can be harmful. Children age 9 years and older, adults, and pregnant and breastfeeding women who take more than 4,000 IU a day of vitamin D might experience:
Nausea and vomiting
Poor appetite and weight loss
Constipation
Weakness
Confusion and disorientation
Heart rhythm problems
Kidney stones and kidney damage