Um....not too sure about calcium citrate causing kidney damage. After all it is what is administered to patients in hospitals with kidney duress.
An adolescent should get at least a 1,300mg a day of calcium. That's at least 3 glasses of milk. And depending on which health authority you ask, some suggest that adults should take a gram of supplemental calcium in addition to foods high in calcium such as milk. I personally would rather supplement with it. Dairy products bloat me and constipate me. I'm sure some of you suffer from the same.
I don't think the cost of your product is worth $30. I'm assuming that this is for a one month supply? Your website doesn't seem to make it easily clear as to how many days worth of a supply this supplement is. So I can only assume.
I think the best thing people can do is get a reasonably priced multi-vitamin like Centrum or One A Day and add more with specific vitamins and minerals as no multi-vitamin is perfect. Customize a program right for you. For instance, add more calcium if you're female, take heavy steroid cycles, are older and have a family history of osteoporosis. I personally think all people should take at least 2 grams of vitamin C a day as your body can't store it like minerals. I don't get colds when I take this much vitamin C on a daily basis. Lycopene is great for prostates, One A Day has this in a "Men's Formula".
I purchased Centrum for $10 at CVS. It has 180 tabs, So my multivitamin costs me $20 a year.
Just my two cents. I'm not here to promote a product.