D3 Cycle


Reptiles rely on heat, light, UV-A/UV-B, food and water to sustain them and further the bloodlines.

We as responsible keepers should do all that we can to replicate these wild indicators as closely as current technology allows. At Arcadia Reptile we are proud to offer our customers access to more science and emerging thoughts and tech than any other brand. We’re determined to see our ‘Revolution in Reptile Care’.

The D3 Cycle is a chemical and hormonal change in the body of an animal, which goes on to produce vitamin D3.

This is a biological process that is dependent on many external factors including access to natural light, heat, cool and rest.

This amazing process begins when a cholesterol called pro vitamin D (7DHC) is produced in the animal’s skin (it is a natural process in humans too). When this cholesterol is exposed to natural light (including light in the UVB wavelength (290-315nm)), this cholesterol is turned in the skin membrane into pre vitamin D.

After exposure to warmth, this newly manufactured pre-vitamin D is converted (in the skin membrane) into vitamin D3. Vitamin D3 is then sent out into the blood plasma and is bound with a vitamin D binding protein. This is then carried to the liver where this part of this vitamin is converted to a hormone called calcediol (25-hydroxy vitamin D3).

The blood carries this calcediol all around the body and into the kidneys where some of the hormone is turned into another hormone, called calcetriol. This compound then plays an essential role in calcium metabolism and controls the levels of calcium in the blood. Calcetriol also plays a huge role in the immune system and the cardiovascular system. It has been shown to lower the risk of cancers in the body and skin.

So, we can see that exposure to natural sunlight is only the start of this amazing ability in reptiles and humans alike, to turn sunlight into life saving vitamins. If part of the cycle is missed out, then it cannot be completed properly. Changes and reactions would also be unable to be completed. This would result in an under-provision of essential vitamins and hormones, and if supplementation were not used, a calcium crash could happen.

It is worth noting that although vital to the well-being of reptiles, UV exposure plays many more roles in the body than just the D3 cycle. Impacts on sight, breeding and mental well-being are all documented and undergoing continued research.