Well regular sleeping during the day might damage health. Try avoiding it if possible as research has been conducted which suggests that there is a linkage between irregular sleep and hormone production.
Evidence also suggests that lack of sleep won't do you as much damage as irregular or day sleep. I suggest try changing your profession. If that isn't possible due to personal or social reasons then I'd say try adjusting your shift so you can sleep at night.
Erratic sleep is bad no matter what. While you might be able to reduce the effects bit napping at night, it won't make much difference.
You have Vitamin D deficiency because of lack of exposure to sunlight and pills and taking walk in the sunlight can fix that easily.
Growth Hormone deficiency does as a matter of fact effect your sleeping pattern and vice versa. I don't know your age neither am I a doctor but assuming you are young enough, this can be fixed by medical help and change in habits.
...shifted sleep appears to disrupt gene activity even more than not getting enough sleep, according to the research.
In a study published in PNAS, 22 young, healthy subjects were tested in a sleep lab. Interrupting their sleep so that their longest period of sleep was from noon until about 6:30 p.m., they found
On the days of shifted sleep... the number of genes tied to the body's clock dropped dramatically, to 228 genes, or only 1 percent of genes analyzed. ...The researchers estimated that the sleep disruptions would ultimately impact about a third of a person's genes.
This is significantly more than found in studies done on sleep deprivation.
"We think that may be related to the negative health outcomes associated with long-term shift work," Dijk said. Shift workers are at higher risk for many health problems, including obesity, diabetes, high blood pressure, heart disease, disrupted menstrual cycles and cancer, he said.
Growth hormone deficient children have a significant decrease in total sleep time, efficiency, movement and in non-rapid eye movement sleep stage 2.