Calcium, D3, and supplements

The usual pattern

Insect-eating lizards and amphibians in this library are dusted with calcium. A common keeper rhythm is calcium at most feeds and a multivitamin less often, with vitamin D3 used when the animal does not have reliable UVB. Animals with a proper UVB gradient usually still need plain calcium. Follow a reptile vet if the animal is breeding, growing poorly, or already has metabolic bone disease.

Gut-loading

Feed the insects a calcium-rich diet before they are offered. Dust sits on the outside. Gut-loading puts minerals inside. Neither one rescues a diet of waxworms.

Tortoises and beardies

Mediterranean tortoises need weeds and greens high in fiber and calcium, not fruit and not spinach as a staple. Bearded dragons shift toward greens as they grow, with insects still on the schedule. A powder does not repair a diet of mealworms and banana.

When powder is the wrong tool

A swollen limb, a soft jaw, or a twisted spine needs a veterinarian and a husbandry review. Adding three brands of calcium on top of an undiagnosed kidney problem can do harm. Do not copy a dose from a mammal product.

Storage

Keep powders dry, dated, and closed. A clumped tub in a humid room is not doing the job you think it is.