In addition, living at higher latitudes with lower sunlight exposure is positively associated with cancer mortality [ 2].
Decreased vitamin D levels tend to be more common in regions of lower sunlight exposure, such as the South and Southeast of Brazil.
Alternate potential contributory factors may be a direct impact of cold temperatures on blood pressure [ 26, 27], lower sunlight exposure and reduced vitamin D production in fall/winter [ 28], or acute illnesses such as influenza.
Clues to the potential role of vitamin D in the development of rarer cancers have come primarily from ecologic studies which observed lower rates of ovarian cancer (11, 14– 17), endometrial cancer (18), and non-Hodgkin lymphoma (5), among other cancers, in areas with high sunlight exposure (the main source of vitamin D) as compared with regions with lower sunlight exposure.
"It heals slower in cooler, lower-sunlight conditions, and even slower in winter".
One frequently postulated cause of the 'juvenile effect' is the gradual decrease in the shading from the canopy as young trees grow taller (Francey and Farquhar [1982]); The photosynthetic rate increases as trees receive more sunlight, lowering the relative pressure of intercellular to ambient CO2, causing δ13C to rise.
These droplets are seeds that can grow into clouds, and clouds reflect sunlight, potentially lowering temperatures.
While many photovoltaic start-up companies are concentrating on increasing the efficiency with which their systems convert sunlight, Nanosolar has focused on lowering the manufacturing cost.
Cross-sectional studies cannot answer the question of whether vitamin D deficiency leads to cognitive decline, or whether people with a cognition disorder have lower exposure to sunlight or lower vitamin D intake, nor do they reflect seasonal fluctuation of vitamin D status.
Lowering the temperature and limiting the inflow of sunlight also occur as a consequence of volcanic activity.
