Discussion: Blood tests indicated a deficient level of vitamin D. Should I be exposed to the sun or use supplements as suggested to me?

Controlled exposure to the sun has additional benefits beyond the immediate production of vitamin D3. (appropriate safety rules, including wearing a hat and sunglasses, are recommended for patients with autoimmune diseases.

The sun is the source of life on Earth, but people mistakenly avoid controlled sun exposure. Most people today have a chronic vitamin D deficiency. The additives in sun exposure are not absorbed as they would be in the natural fortification process. Vitamin D3 is a cholesterol derivative that has a far-reaching effect on the immune system, as many recent studies have shown in the context of the coronavirus.

Link: Vitamins D3, B12, and Omega-3 are critical for proper immune function.
https://www.sf-healing.com/page/135 (Copy & Paste)