Final answer:
Too little UV light exposure can lead to vitamin D deficiency, which is linked to health issues like osteoporosis and certain cancers, and decreased levels of vitamin B9, important for reproduction.
Step-by-step explanation:
Too little ultraviolet (UV) light can lead to a deficiency in vitamin D production in the skin, which is essential for bone health, and plays a role in the immune system.
Vitamin D deficiency is associated with several medical problems such as osteoporosis, and an increased risk of certain cancers including prostate, breast, and colon cancers.
Additionally, insufficient UV exposure can also lead to decreased levels of vitamin B9 (folic acid), important for reproductive health and preventing birth defects.
Protection from ultraviolet radiation is vital, but small amounts of UV-B, the type of UV light that stimulates vitamin D production, are beneficial for health.