The recommended dietary allowance for vitamin D is 600 IU (international units) per day for adults up to age 70. People aged 71 and older should aim for 800 IU from their diet. Some researchers recommend much higher doses of vitamin D, but too much vitamin D can hurt you. Above 4,000 IU per day, the risk for harm rises, according to the Institute of Medicine.
Drugs That Interact With Vitamin D
Some drugs cause your body to absorb less vitamin D. These include laxatives, steroids, and anti-seizure medicines. If you take digoxin, a heart medicine, too much vitamin D can raise the level of calcium in your blood and lead to an abnormal heart rhythm. It’s important to discuss your use of vitamin D supplements with your doctor or pharmacist.