Abstract
During the past four years a study has been made by us of the seasonal variation in the antirachitic effect of sunshine. From the results reported<sup>1</sup>it was concluded that the sun's rays during the latter part of October, all of November, December and January and the first part of February in the latitude of Toronto produced a slight but definite antirachitic effect, which sharply increased about February 15 and continued throughout the summer at approximately eight times the winter level. A marked decrease in the antirachitic effect occurred about October 15. It was further found<sup>2</sup>that this change in antirachitic effect is apparently largely dependent on the altitude of the sun above the horizon. When the sun is low in the sky the rays necessarily pass through a greater amount of the earth's atmosphere, and the short, biologically active ultraviolet rays are markedly diminished. A critical altitude
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
