Vitamin D is fat-soluble, so dosing daily isn't required (the excess is stored and not excreted in urine). The 5k and 10k IU pills are useful because you can po

Vitamin D is fat-soluble, so dosing daily isn't required (the excess is stored and not excreted in urine). The 5k and 10k IU pills are useful because you can pop a few on weekends (or whenever you remember) and don't need to build a daily habit.