Tanning bed
Unlike the sun, tanning beds do not help the body produce vitamin D as their bulbs emit mostly UVA light. The human body needs UVB light to produce vitamin D. Both the sun and tanning beds can damage your skin if you stay exposed for too long.  Getting too much UV, or many sunburns can cause skin cancer, including melanoma, which can be deadly.  There is a lot of controversy due to the risks.  Most countries have many laws and rules that regulate tanning beds.