Rep-Cal SRP00200 Phosphorous-Free Calcium Ultrafine Powder Reptile/Amphibian Supplement with Vitamin D3 Review (2026)

What this supplement is built to do

Rep-Cal SRP00200 is a phosphorous-free calcium carbonate powder, milled to an ultrafine grind and fortified with vitamin D3, sold in a 3.3 ounce container. It is meant for reptiles and amphibians that rely on keepers to supply calcium since captive diets and indoor lighting rarely match what wild animals get from bones, shells, or strong sun. The calcium comes from natural oyster shell, and because it carries no phosphorus, it will not throw off the calcium to phosphorus ratio that many feeder insects already skew toward phosphorus. Vitamin D3 is added to help the body absorb that calcium, which matters most for animals kept under weak or no UVB lighting. This is a supplement for the food, not a treatment, and it does not replace proper lighting, heat, or a varied diet.

How the powder behaves in practice

The ultrafine milling is the detail that matters day to day. Coarser calcium powders tend to fall off crickets, roaches, and greens by the time the animal eats them, while this grind clings after a light shake in a bag or dusting cup. Keepers commonly pair it with a multivitamin powder like Herptivite in a roughly equal mix, shaking feeder insects in the combination just before offering them so both products stick in one pass. For leafy greens and vegetable mixes fed to omnivorous or herbivorous species, a light dusting over the food right before serving works the same way. Because the container does not list volume on the front panel, it is worth checking the listed net weight before ordering if you are supplementing a large collection and want to know how many feedings one order will cover.

Where D3 helps and where it needs care

Vitamin D3 lets an animal use dietary calcium even without much UVB exposure, which is why this version exists alongside a plain, D3-free Rep-Cal. The tradeoff is that D3 is fat soluble and builds up in the body over time, so feeding a D3 formula at every single meal to an animal that also basks under good UVB lighting can push D3 intake higher than needed. Most reptile veterinarians and experienced keepers suggest rotating a D3 calcium with a plain calcium through the week, leaning more on the D3 version for animals with limited UVB access and more on plain calcium for those with strong UVB or frequent natural sunlight. If you are unsure how to balance this for a specific species, a reptile veterinarian or the care sheet for that animal is the better guide than a general rule.

How it sits next to other calcium powders

Within the calcium and supplement lineup, Rep-Cal SRP00200 sits close behind Zoo Med's Reptile Calcium with D3 and just ahead of Nekton's Rep-Calcium+ D3 and Exo Terra's Calcium plus D3 powder, all of which do the same basic job with small differences in grind, container size, and brand reputation. Rep-Cal's main edge is decades of use in zoo and veterinary settings, which counts for something when you want a formula with a long track record rather than a newer entrant. Zoo Med's version is a close rival on fine texture and wide availability in US pet stores, while Nekton's tub is harder to find locally but offers a larger fill. None of these differ enough in real-world results to be a dealbreaker; the choice mostly comes down to container size, price per ounce, and what your local store stocks.

Who should buy it and who should look elsewhere

This is a solid pick for keepers who feed insects or fresh produce regularly and want a calcium powder with a long history behind the formula rather than a newer brand. It suits insectivorous and omnivorous reptiles and amphibians especially well, since the ultrafine grind is made to coat live prey. Keepers who already have a D3 calcium on hand, or whose animals get consistent strong UVB and do not need extra D3, may be better served buying the plain, phosphorous-free Rep-Cal instead and adding D3 separately through diet or a multivitamin. Anyone new to reptile supplementation should check the feeding frequency and D3 rotation advice for their specific species before starting, since needs vary a lot between a leopard gecko under weak lighting and a bearded dragon basking under strong UVB.

Frequently asked questions