If short of Vitamin D3, easy to get sick and feel depressed. Also, there is no overdose issue. I am very happy to have this product. I take 2 other product by HFL - all give great results
Four stars because I need to get blood work done to see if it's really working. I want my level to be between 40 and 60. I switched over from Naturemade D3 5,000 IU. This is capsules versus Naturemade powder which is oil-based with soybean oil.
This also has the important K2/MK7 that most products do NOT have. I will update later on with vitamin D numbers from my lab work in the future. I do feel sharper and more energy after this supplement, and I see other doctors recommending this brand. I hope all other reviews are genuine and authentic.