Does season affect your chance of vitamin D deficiency?
This chart demonstrates the profound influence that season can have on vitamin D levels and risk of deficiency, which increases with increased distance from the equator. During the summer time, for example, there is a 70% decreased risk of vitamin D deficiency compared to the winter time.
Seasonal trends have been observed in several diseases. In an effort to maintain a target serum level of 40-60 ng/ml throughout the year, GrassrootsHealth recommends measuring the vitamin D serum level at the end of summer (October) and at the end of winter (March), and adjusting intake or vitamin D routine accordingly.
Chart Date: 05/05/2017