Zoo Med Reptile Calcium with Vitamin D3, 8-Ounce Review (2026)

What this supplement is for

Zoo Med's Reptile Calcium with Vitamin D3 is a fine powder made mainly from precipitated calcium carbonate with added cholecalciferol, the D3 form used in most reptile supplements. Keepers dust feeder insects like crickets or roaches with it right before offering them, since most captive reptiles and amphibians cannot get enough calcium from insects alone. The added D3 helps the body process that calcium into bone, which matters most for animals that get limited or no direct UVB light. Species commonly dusted with a D3 calcium include leopard geckos, crested geckos, bearded dragons and many amphibians, though exact dusting frequency depends on the individual animal's UVB access and life stage, which a species-specific care sheet should guide.

Formula and what is in the container

The listed analysis puts calcium in the 35 to 40 percent range with roughly 220,000 IU of vitamin D3 per kilogram, and the formula is phosphorus-free, which matters because reptile diets built around insects tend to run high in phosphorus relative to calcium already. The 8 ounce size comes in Zoo Med's typical shaker-top container, letting a keeper dust insects directly in a bag or cup without extra tools. For a single reptile or a small collection of two or three animals, 8 ounces lasts many months of regular dusting, which is part of why the value score on this listing runs high relative to the smaller 1 to 2 ounce sizes some competitors sell.

Using it day to day

The standard approach is to place feeder insects in a bag or container, add a small amount of powder, and gently shake until they are lightly coated before offering them to the reptile. Because this version includes D3, it should not be used at every single feeding for reptiles that already get strong UVB exposure from a quality bulb or natural sunlight, since too much supplemental D3 on top of UVB-driven D3 synthesis can push levels higher than intended over time. Many keepers rotate between this D3 formula and a plain, D3-free calcium powder through the week, following the schedule recommended for their specific species rather than dusting every feeding with the same product.

Where it fits against other supplements

Within the site's calcium and supplement guide, this product ranks at the top of seven options, ahead of well-known alternatives like Rep-Cal's phosphorus-free powder and Nekton's Rep-Calcium. Zoo Med's formula lands in a similar niche to those competitors: a phosphorus-free, D3-inclusive dusting powder aimed at the mainstream of pet reptile keeping rather than specialized breeding programs. Compared with a multivitamin product like Herptivite, this is a calcium-first formula and does not replace a broader vitamin supplement in a rotation, so many keepers stock both a calcium with D3 and a separate multivitamin rather than relying on one product for every nutritional need.

Who should buy it

This is a solid default calcium supplement for keepers of common pet reptiles and amphibians who feed insects and want a phosphorus-free, D3-inclusive powder from an established reptile-supply brand. It is not the right single product for a keeper who needs a phosphorus-free calcium without any D3, since animals under strong UVB or those with certain health conditions sometimes need a D3-free formula instead, which Zoo Med also sells separately. Anyone unsure how often to dust with a D3 product for their specific species should check a care guide or a reptile veterinarian rather than guessing at a schedule.

Frequently asked questions