Carlson® Wild Norwegian Cod Liver Oil-Lemon comes from deep, unpolluted waters. Carlson brings you the finest cod liver oil, naturally rich in Vitamin D3 with Vitamin A. Only cod fish caught during winter and early spring are used, as the liver oil content is highest at these times. The oil is separated from the liver tissues without the use of chemicals. To ensure freshness, air inside the glass bottle has been replaced with nitrogen. Gluten free.