Vitamin D: Light side and best time of sunshine in Riyadh, Saudi Arabia.
Low levels of 25-hydroxyvitamin D have been documented among inhabitants of the wider Middle East and North African countries. Sunlight has long been recognized as a major provider of vitamin D. In this study we aimed to determine the optimum time for sun exposure in the Central region of Riyadh, Saudi Arabia. Ampoules containing 7-dehydrocholesterol in ethanol were exposed to sunlight every hour starting from sunrise until sunset in July and December. Our results demonstrated that the time of the day has a major influence in vitamin D production. In this study, summer production of previtamin D3 was observed to occur between 8:00 PM to 4:00 PM with peak hours between 10:00 AM to 12:00 PM. During wintertime however, the conversion began later at around 9:30 AM and ended sooner at 2:00 PM, with peak hours at 10:00 AM to 12 noon. In conclusion, the optimum time to get sun exposure for vitamin D3 production in Riyadh, during summer is from 9:00 AM and before 10:30 AM, as well as after 2:00 PM until 3:00 PM, while during winter it's from 10:00 AM until 2:00 PM. These times are important on a public health perspective, as it's free, relatively safe and the most enjoyable. This strategy is a highly efficacious way for improving the vitamin D status for children and adults and preventing vitamin D deficiency.
King Saud bin Abdulaziz University for Health Sciences and Family Medicine; King Abdulaziz Medical City; National Guard; Riyadh, Saudi Arabia.
Fahad M
FM
Alshahrani
Specialized Diabetes and Endocrine Center; King Fahad Medical City; Faculty of Medicine; King Saud Bin Abdulaziz University for Health Science (KSAU-HS); Riyadh, Saudi Arabia.
Mussa H
MH
Almalki
Specialized Diabetes and Endocrine Center; King Fahad Medical City; Faculty of Medicine; King Saud Bin Abdulaziz University for Health Science (KSAU-HS); Riyadh, Saudi Arabia.
Naji
N
Aljohani
Department of Family Medicine; King Abdulaziz Medical City; National Guard; Jeddah, Saudi Arabia.
Abdullah
A
Alzahrani
Department of Endocrinology; King Abdulaziz Medical City; National Guard; Riyadh, Saudi Arabia.
Yousef
Y
Alsaleh
Department of Medicine; Section of Endocrinology, Nutrition, and Diabetes; Vitamin D, Skin, and Bone Research Laboratory; Boston University Medical Center; Boston, MA USA.
Michael F
MF
Holick
Riyadh, Saudi; Vitamin D; exposure; sun; time