I pee pure vitamin D now

So, my old lady calcium supplements (I went with vaguely caramel flavored chews rather than suppository sized pills) have 50% of my daily value of calcium, and 125% of my daily value of vitamin D, and instructions to take twice a day. So my question is, why do I need 250% of my daily value of vitamin D, or is it really impossible to make vaguely caramel flavored chews with any less vitamin D than these? I could be a photophobic albino and these pills would keep me swimming in vitamin D.