Vitamin D3 supplements (60,000 IU)

Hi, does anyone know if one can find 60,000 IU D3 supplements in Tokyo? The ones that you can take orally once weekly. If not, any alternatives for a severely D-deficient (egg-eating vegetarian…) person to help increase their stored D3? I'm willing to go to doctors about this for prescription-strength medicines if needed (does anyone know what types they offer?).

I've been diagnosed officially and would have got these supplements from my home country but had to return here on short notice.

Thanks so much!