Don’t take anything on your own. Get bloodwork. Your doc will know how much to tell you to take from the bloodwork. I take 2400 mg of calcium per day and 10,000 IU of vitamin D3. Doc determined I needed these amounts. You can actually build up a toxicity if you get too much vitamin D in your system. Not sure about the calcium. Definitely get bloodwork done. I get mine done every 6 months, sometimes more often than that.