The Importance of UVB Light for Reptiles

December 28, 2020

Leopard gecko looking at a worm

UVB Lighting for Reptiles

In the wild, reptiles and amphibians are provided with ultraviolet light from the sun. These ultraviolet rays cause reptiles to synthesize vitamin D3, which helps them to absorb calcium. Reptiles in captivity will not be able to get these rays from the sun, therefore we must supply them with this lighting. This can be done by providing them with UVA and UVB bulbs. These bulbs put off very little heat so they should be used with a heat bulb, not in place of one.


Why is UVB Important for Reptiles?

UVB lighting is important for reptiles because it allows them to synthesize vitamin D3 and absorb calcium. Without the ability to absorb calcium reptiles can develop metabolic bone disease (commonly seen in captive bearded dragons). This leaves their bones brittle and prone to fractures. This can also cause deformities in the bones (commonly the spine), and in extreme cases can lead to death. UVB is also known to stimulate appetite, and increase your reptile’s activity levels. 



Do Snakes Need UVB?

Snakes don’t require UVB to survive because they get the appropriate amount of calcium and nutrients from the rodents they eat. However, UVB can be beneficial to snakes in many ways. It has been known to increase their appetites, make them more active, and give their overall appearance a more vivid coloration. I use UVB in my corn snake’s enclosure, and I believe that it makes him more active and improves his overall well being.


boa constrictor sunbathing


What Reptiles Require UVB Light?

Almost all diurnal reptiles such as crocodiles, tortoises, and lizards require UVB light.


These reptiles require UVB lighting:

  • Monitor Lizards
  • Tegus
  • Bearded Dragons
  • Chameleons
  • Sulcata Tortoises
  • Green Iguana 
  • Green Tortoises
  • Red-Eared Sliders
  • Blue Tongue Skinks


These Reptiles Do Not Require UVB Lighting:

It should be noted that although these reptiles don’t “require” UVB lighting, they can all still greatly benefit from it being supplied to them, therefore I recommend you providing them with UVB.

  • Corn Snakes
  • Ball Pythons
  • Leopard Geckos
  • Crested Geckos
  • King Snakes
  • Tree Pythons
  • Tokay Geckos
  • Fat-Tailed Geckos
  • Rosy Boas
  • Carpet Pythons



Best Reptile UVB Bulb?

Reptiles, such as bearded dragons, that require UVB to live happy healthy lives, will need a bulb that has a high output of UVB. Other reptiles, such as snakes, that do not require UVB can be supplemented with a UVB bulb that has a lower output. Your reptile cannot overdose on UVB lighting, so whichever light you choose to provide them with should be fine. They can however overdose from too many calcium supplements (such as a high quantity of calcium dust) in their food, so be cautious of that. 


bearded dragon sunbathing


Remember to change out your UVB bulb every 6 months. The bulbs will still put off light after 6 months, however they will not put off UVB. Another important thing to remember is that both glass and plastic lids will filter out UVB, defeating the purpose of having the bulb. Screen lids work better when paired with a UVB bulb, but will still filter out a percentage of it. The bulb should be somewhat close to your reptile as well (about a foot away) or they will not fully benefit from the rays it puts off.