There has been quite a bit said about full-spectrum lighting (FSL, grow lights or plant lights) and their ability to cure or influence many ailments and illnesses. The theory goes like this; based upon seasonality (spring, summer, fall, and winter) and a dog's living environment (indoors or outdoors), some dogs may not receive sufficient amounts of sunlight and as a result do not synthesize enough vitamin D. Since vitamin D is necessary to stimulate proper estrogen production it is considered an important component of proper estrous cycling in the bitch.
The proposed solution to this problem is the use of FSL in the breeder's home and kennel. While the problem is likely real, the
proposed solution may not hold much water and here is why:
Vitamin D is synthesized by the body when stimulated by sufficient intensities of ultraviolet light (yes, the same UV light that is linked to skin cancer in
humans...so this is a double-edged sword). Under natural sunlit conditions, one can absorb enough UV radiation
in about 20 minutes to affect vitamin D levels.
FSL bulbs do not offer a high dose of UV light and so the time of exposure required to stimulate the same vitamin D production is approximately 30 hours per day.
In case that last figure did not grab you, let me repeat it. Approximately 30 hours of daily exposure to FSL bulbs is required to increase vitamin D production. That is more than is available in a day and as a result, one must conclude that FSL bulbs can have little or no real effect on vitamin D production in the dog and as a result will have no influence upon moderating or regulating a bitch's breeding cycle.
Note the difference in intensity (power) of light in the range required to stimulate vitamin D production (315-400nm). Indeed, FSL bulbs produce no measurable light energy below approximately 375nm.
For more information on this fascinating topic visit the Lighting Research Center website.