Paraboy is correct, your goal is 80 ng/ml but you need a LOT more than 1,000 IU daily. You should start at 10,000 IU Daily of oil based Softgels. Then after 3 months get your blood tested for D3. You can get an inexpensive $65 at home blood test here: https://vitamindcouncil.zrtlab.com/index.php?option=com_virtuemart&view=produ...
After your D3 report, raise or lower your dosage by 1,000 IU for every 10 points on the blood test to achieve 80 ng/ml. Most adults require between 7,000 to 12,000 IU to achieve their goal of 80 ng/ml