The half-life of D3 is ~24 hours. The half-life of 25(OH)D is ~3 weeks. Weekly dosing is OK for bone health. For everything else you need to supplement daily. Dr. Bruce Hollis - Vitamin D Dosing Interval https://youtu.be/FbheaULwRAk
“One pill every two weeks fights diabetes, cancers, heart failure, and 18 other diseases.”
Dr. Bruce Hollis - Vitamin D Dosing Interval
https://youtu.be/FbheaULwRAk