Nekton Rep-Calcium+ D3 Reptile Supplement 130 gm (4.56 oz) Review (2026)

What is in the tub

Nekton Rep-Calcium+ D3 is a calcium and vitamin D3 supplement built around calcium carbonate and magnesium carbonate, with the manufacturer listing roughly 37 percent calcium content by analysis. Beyond the core calcium and D3, the formula adds two amino acids and a set of trace minerals including iron, zinc, manganese, copper, iodine, and selenium, aimed at supporting broader nutrition rather than calcium alone. It comes in a 130 gram, 4.56 ounce tub with a measuring spoon included, where one level spoon holds about 1 gram of powder, giving a simple way to measure out consistent doses rather than guessing at a pinch or shake.

How to dose and use it

Nekton's own guidance suggests roughly 0.25 grams per kilogram of body weight daily, or about 1.5 grams once a week as an alternative schedule, figures worth adjusting for the specific species and life stage since juveniles, gravid females, and adults often need different amounts. The powder is not water soluble, so it is meant for dusting or coating feeder insects and other food rather than mixing into drinking water. For insectivorous reptiles and amphibians, the standard method is shaking insects gently in a bag or container with a small amount of powder just before feeding so it coats their exterior without clumping.

The daily ration cap and why it matters

Nekton states this supplement should make up no more than about 3 percent of an animal's daily ration, a cap tied to its higher vitamin D and trace element content compared with a basic complete feed. This lines up with the general advice around any D3-fortified calcium, since D3 is fat soluble and can accumulate if fed at every meal without a break, particularly for animals that also get strong UVB exposure from lighting or sun. Rotating this D3 formula with a plain, D3-free calcium through the week is the common approach experienced keepers use to keep total D3 intake in a reasonable range while still covering baseline calcium needs at every feeding.

Storage and handling

Nekton specifies storing the tub dry and away from sunlight, at a temperature between about 59 and 77 degrees Fahrenheit, and is explicit that it should not go in the refrigerator, since cold, humid conditions there can affect the powder's texture and consistency over time. A cool, dry cabinet away from a terrarium's heat and humidity is the more practical spot for most households. Keeping the lid tightly closed between uses also helps prevent the fine powder from absorbing ambient moisture and clumping, which would make it harder to get an even, light coating onto feeder insects.

How it compares and who it suits

Among calcium and D3 powders for reptiles, Nekton's tub sits close in score to Rep-Cal's phosphorous-free version and just behind Zoo Med's Reptile Calcium with D3, with the main practical differences being fill size, grind, and how easy each brand is to find locally. Nekton's 130 gram size is a generous fill compared with the 3.3 ounce jars common from Rep-Cal and Zoo Med, which suits keepers with several animals to supplement, though it can be harder to find on shelves in US pet stores and often needs to be ordered online. This supplement suits keepers who feed insects regularly and want a formula that also covers trace minerals and amino acids, provided they follow the daily ration cap and rotate with plain calcium as needed.

Frequently asked questions