Sunlight is a good approximation of the entire light spectrum, and in proportions that are the most healthy. However, even sunlight can produce harm. carelessly consumed, so some precautions are necessary, such as sun screen, sunglasses, time of day of exposure, and the total time of exposure carefully calibrated to each individual's needs.
On the other hand, we modern people spend enormous amounts of time indoors under artificial lighting, and there are problems associated with that. The effects of electricity, in general, are not thoroughly known, and the spectrum of light that all these bulbs cover is far narrower than we imagine.
In general, the spectrum runs from Ultraviolet to Infrared, with these two extremes being the most cautionary parts of the spectrum. There exist bulbs that give you the best amounts of both, but they are usually created for, and used for, special purposes. For example, Ultraviolet is commonly used to kill germs, while Infrared is most commonly used for deep tissue heating as as physical therapy.
The area in between is more or less covered by fluorescents and incandescents. One trick is to use, (perhaps over your desk) a combination of both of these that will give you some approximation of sunlight. There are now special fluorescent bulbs that claim to combine both. They are called sunshine bulbs.
The problems related to artificial light are widely and intensively under study and research as to their effects, compared to the ideal of proper exposure to sunlight. For the time being we do what we can to guard our health and those we care about, with moderation always being the watchword.