I tend to have chronic immune system problems. I had been taking 50000 ius of D3 and had a blood level test that said my Vit. D level was good. However, I'd had a chronic, mild sore throat for the two months at the time I began taking this emulsified D3. Could be coincidence, but the sore throat stopped after taking this product for three days. I might add that I have celiac disease and hashimotos hypothryoid, which can make absorption of nutrients difficult. I think this product did the trick