I am not sure about the vitamin D deficient diets but i guess (never done it) UVB actually contains vitamin D to be manufactured with skin

Can have a glass (again not sure) which filters out UVB rays if a dark room is not available

regards

Hi Sikandar

What type of glass? Is it normal glass or tinted ones?

I am in the same problem as you. Why not try to cover the cages with black cloth or black paper.

Hi Fairrouz

I thought about covering the cages but im worried about the ventilation

Isnt it just sunlight that is the culprit, if there are no windows, just darkened cages should be enough, not letting in the room light, also mice are usually in dark areas in the wild most of the time? Just what is the appropriate vitamin D level for a mouse? not sure its a valid comparison to humans really?

If I’m not wrong, the lad animals get the ingredient from their chow, not from incandescent bulbs or fluorescent tubes which do not emit UVB. If this is the case, to block the lab light may not help at all, but alter the circadian clock in these animals because of the change of light/dark cycle.

Dear professor Weiguo Zhang

more details please, concerning the inconvenience of blocking laboratory lights.

Ultraviolet B (UVB) is essential for cutaneous synthesis of vitamin D from its precursor molecule (e.g. 7-cholesterol) in most terrestrial mammals. It is then very necessary to know whether the indoor rays from fluorescent tubes (or maybe incandescent bulbs) in your animal room are full-spectrum/all wavelength. If not, in particular if no UVB emitted, to block lab lights should have discernible impact on your results (suppose you have study and control groups, and both are kept in same conditions, e.g. light/dark circle, temperature). In general, it’s not proved that the lab rodents get vitamin D required from UVB exposure.

Dear professeur Weiguo Zhang

Thank you very much for your valuable answer.

Prof. Zhang

Thank you very much for the answer.