Vitamin D could improve fertility, study finds
A study of wild sheep living on a remote Scottish island has added to growing evidence that the "sunshine vitamin" - vitamin D - improves fertility.
Scientists from the University of Edinburgh found that sheep with higher levels of vitamin D in their blood at the end of the summer had more lambs the following spring.
The researchers studied an unmanaged population of Soay sheep on St Kilda in the Outer Hebrides, where sheep have lived wild for thousands of years.
It is hoped the research will help other mammals, including humans. Vitamin D is produced in the skin of sheep and many other animals, including humans, after exposure to sunlight.
Many studies have linked vitamin D to reproductive health in animals and humans but this study is the first evidence of the link in wild animals.
Dr Richard Mellanby, head of small animal medicine at the university's Royal (Dick) School of Veterinary Studies, who led the research, said: "Our study is the first to link vitamin D status and reproductive success in a wild animal population.
"Examining the non-skeletal health benefits of vitamin D in humans is challenging because people are exposed to different amounts of sunlight each day.
"Studying the relationship between skin and dietary sources of vitamin D - and long-term health outcomes - is more straightforward in sheep living on a small island."
The research was published in the journal Scientific Reports.