cats wrote: I also wonder if you considered using a tanning bed, since you can't get sun exposure during this season?
If you do decide to use a tanning bed do check the UVB output of the tubes used.
There is a great variation and many (those primarily used for fast tanning) that have a very high UVA output and very low UVB output. It's the UVB that acts on 7-Dehydrocholesterol that results in Cholecalciferol Vitamin D3. I use ones with 5% UVB output. Short exposures are important. It's also important to ensure you NEVER burn. Much of the DNA damage that leads to skin cancer comes from the oxidative damage from iron released from the blood when the skin is inflamed, which is why we must avoid sunburn.
It also helps if you become a blood donor as regularly giving blood reduces the chance of iron overload.
Melatonin and curcumin are good iron chelators that stop excess iron behaving badly. Health Fellow Natural Sunscreen Options
has some sensible suggestions for improving your ability to withstand UVB exposure safely.
Remember humans evolved outdoors wearing little if any clothing and having pale hairless bodies proved advantageous to those living away from the equator. In order to benefit from that evolutionary advantage pale near hairless bodies provided for outdoor lving near naked humans we have to STORE vitamin D in tissue and this only happens in significant amount at 25(OH)D levels above 40ng/ml and ideally around 60ng/ml.