It can also be used as a custard-like base for pies or fruit shakes. If you are unable to get the appropriate amount of calcium for your body size and age solely through your diet, a calcium supplement may be appropriate. Vitamin D is necessary for calcium absorption. Exposure to sunlight usually allows your body to manufacture as much Vitamin D as you need. Ten to 15 minutes of sun exposure a day is adequate.
Vitamin D is also available in supplements and in some fortified foods.
Taking supplements with more than the RDA of Vitamin D can be harmful. Vitamin C has many functions in the body, including the production of healthy connective tissues, and the healing of wounds and fractures. It is fairly easy to get adequate Vitamin C through the diet. There is some evidence that Vitamin C tablets can increase the risk of kidney stones in people who already have high levels of calcium in the urine. Because high urine calcium affects some people with OI, check with a physician before taking Vitamin C supplements.