Calcium with vitamin D4?

[smay2010]

I know reptiles need calcium with D3, but out of curiosity what is the difference between the calcium with D3 and the calcium with D4? D4 helps absorb calcium and eliminate phosphorous.

 

[brittani299]

I have never heard of d4 before. I use calcuim with d3 for both of mine

 

[smay2010]

I know D3 is just the same vitamin you get from the sunlight, but if we use basking lamps to mimic the sun our dragons are already getting D3. Can't they get too much? From what I've been reading about D4 (I hadn't heard of it either) it sounds better for the dragons then potentially oding on D3.
Has anyone used D4?