This section is from the book "The Hygienic System: Fasting And Sun Bathing", by Herbert M. Shelton. Also available from Amazon: The Hygienic System Vol III Fasting and Sun Bathing.
Sunshine stimulates the growth of hair. Under its influence, breathing becomes deeper and slower; sleep sounder, blood-pressure is diminished, and urinary excretion is increased. Ulcers, sores, skin diseases, etc., heal more rapidly under its influence. The skin itself is rejuvenated by such bathing. Sunshine aids in building good teeth. It undoubtedly aids in preserving the normal alkalinity of the blood and should prove an effective aid in restoring normal alkalinity.
There is not a tissue or function in the body that is not favorably affected, either directly or indirectly by sunshine. The sun's rays enable the animal, as they do the plant, to analyze compounds and to synthesize new ones. Sunshine is an essential catalytic agent in both plant and animal life.
The benefits to be derived from sunshine apply to all periods of life, but are greatest during periods of development and rapid gains in flesh. Not enough emphasis has been placed on its value to the unborn child.