Vitamin C is needed as part of collagen formation, stimulates bone (growth/healing?), and protects against oxidation of vitamin A. On the other hand, I suppose even 1/10th that amount would do something.Why so much vitamin C and vitamin A? Vitamin C lowers ceruloplasmin (although vitamin A increases it), and vitamin A itself causes bone loss in that sort of dosage unless you are getting a ton of sunlight or vitamin d.
Vitamin A and D3 could be lessened as mentioned near the end of the post. Vitamin A at that amount for that period of time would be fine given the presence of sufficient vitamin D3 and K2.