How do I know if Durable D3 Complex is working?Updated 11 days ago

The only way to ensure this formula is working for you is to have your vitamin D levels checked through a simple blood test. Dr. Passero recommends taking it for 90 days before doing blood work.

Vitamin D testing can be done through your doctor, or you can order directly through sites like letsgetchecked.com or walkinlab.com which offer direct to consumer lab testing.