Bulksupplements Vitamin D3 (Cholcalciferol) Softgels (300 softgels) is the best in my opinion.... 84% 5 star rated on Amazon

https://www.amazon.com/Bulksupplements-Vitamin-Cholcalciferol-Softgels-softgels/dp/B01ERXX7PA/ref=sr_1_1?crid=1T5XEDFJENR7Q&keywords=bulk+supplements+vitamin+d3&qid=1574196619&sprefix=Vitamin+D3+Supplement+bulk%2Caps%2C648&sr=8-1

or you can buy it direct on their website

https://www.bulksupplements.com/products/vitamin-d3-cholecalciferol?_pos=1&_sid=e4c933378&_ss=r