Taking calcium tablets containing vitamin D3 does not require vitamin D supplementation. Vitamin D3 is a kind of vitamin D, both of which have the function of promoting calcium absorption and preventing osteoporosis, because vitamin D is a fat-soluble vitamin that can be stored in fat for a long time, so if you take calcium tablets containing vitamin D3 and then take vitamin D at the same time, it is easy to cause swollen joints, itchy skin, dry lips, cracked abdominal pain, diarrhea, stomach pain and other symptoms of vitamin D toxicity. Some patients with osteoporosis due to severe vitamin D deficiency cannot ensure sufficient vitamin D intake by simply using calcium tablets containing vitamin D3, so they can use vitamin D in combination under the guidance of a doctor, but note that once the above symptoms of vitamin D toxicity appear, please stop taking the drug immediately and go to the local regular medical institution in a timely manner.