Thank you for getting back to me. I'm afraid that your chameleon may be in a great deal of trouble. The main cause of broken legs in lizards
is, as you already know, Metabolic Bone Disease (MBD). Since your chameleon has two broken legs already, we can reasonably assume that's what is wrong. But she is also gravid, and producing eggs further depletes the body of calcium. You're on the right track with wanting to give calcium, but first you'll need to take care of a problems with the UVB light. UVB lights are only good for 6 months. The UVB rays themselves are not visible to the human eye, but the lights also put out visible wavelengths. After six months, that is all they emit. There are no more UVB rays being produced. That means your chameleon has not had UVB rays for six months. Without UVB, calcium cannot be utilized, so it won't matter how much is included in the diet. In addition, the coil lights are very inconsistent. Even when brand new, they may not put out enough UVB. The first thing you should do is get a new UVB light, a straight tube, preferably with an output of 15.0. I recommend the Reptisun brand. Even with a fresh UVB light, it's difficult for chameleons to produce enough vitamin D without access to natural sunlight. They have a much higher need than many other species. That's why I reommend a 15.0 if you can find one.
You also need to increase the temperatures in the cage. Chameleons are adaptable to temperature extremes in their wild habitat, but there they can move around to find warmer or cooler spots. In a cage they have no choice. Being too cold can lead to inefficient digestion, and less calcium will be assimiliated. The ambient air temperature in the cage should be 26*-32*C. That means the coldest part of the cage should be 26*C. There should be a warm basking area that is kept at 33* - 40*C. You may need another overhead basking light to get that temperature. That doesn't have to be expensive and it doesn't need to come from a pet store. If you live in an area that has farm stores, you can buy a metal light fixture made to keep baby chicks warm for just a few dollars. Don't buy the accompanying bulb, however. You need an ordinary incandescent bulb in the basking light. Hardware stores sell similar reflective fixtures as work lights. Use a good digital probe thermometer to measure the temperature. You can adjust the temperature by raising or lowering the fixture or by changing the bulb to one with higher or lower wattage. If you have to lower the fixture, don't put it so low that your chameleon can touch it and be burned.
When you see the vet tomorrow for the broken leg, ask about calcium. There are high-potency liquids available from vets, or the vet may want to inject calcium to quickly get it into her system. If your climate is mild enough to take her outdoors, carry her out for a supervised sunbath every day. Of course, if it's cold, you won't be able to do that.Windows filter out UVB rays, so sunlight through a window won't do any good. Do be sure to get that new UVB light right away. While your chameleon is recovering, keep her on the lower level of her cage. remove anything she can climb on to avoid further energy.
If you have more questions, just let me know by clicking on REPLY. I hope your chameleon will reach a full recovery.