No, if they are getting artificial UVB, it should be considered a supplemental UVB source. Unless they are in a large cage, and under a properly set up and calibrated mercury vapor bulb, of course.
Zoomed bulbs, and other UVB tubes are not a replacement for sunlight. It is not possible to grow them solely with these lights. You need to also use dietary D3 from a calcium supplement, minerall and repcal are my favorites - I KNOW they work.
Think of the lighting and d3 powder BOTH as supplements - neither is good enough alone, but together, they work perfectly (though not AS good as the sun, of course!). Using the D3 powder in conjunction with the low-output UVB bulbs is great, as the UVB reduces the amount of dietary D3 you HAVE to use. Alone, these bulbs do not produce enough UVB.
Here's what I like to use:
Repcal with D3
Minerall without D3
Reptisun bulbs(5.0 or 10.0, depending on cage size)
I dust almost EVERY feeding, but I only dust one out of every 4 insects I feed, per animal. In other words, if I'm feeding my chameleon 4 insects today, I dust one of them with a mixture of repcal and minerall - usually more minerall than repcal.
Repcal has a LOT of D3 - more than is really necessary. So, I "cut" it with the minerall, which also has trace minerals as well as calcium. I lightly dust the insects, so they do not get too much of anything at any time. I find that if you supplement a little bit, more often, it makes the possibility of oversupplementation lower.
For babies, or animals in growth spurts, I usually dust more than half their insects, but I still dust VERY lightly.
Every week, I usually include one vitamin dusted insect (with herptivite, with NO preformed vitamin A). Every 2-3 weeks, I dust one with reptivite, which has preformed vitamin A.
I know, having 4 supplements seems a bit much, but I find it offers MUCH more verstility. If I put my animals out in the sun I leave out the repcal with D3. If they are eating fruits or veggies high in vitamin A, I leave out the reptivite. If they are growing, or developing eggs, I up the quantity of repcal with D3.
