Infertility rate is 2X higher for blacks than whites (no mention of vitamin D, nor the man)
Infertility, Endured Through a Prism of Race New York Times
‘According to the National Survey of Family Growth, conducted from 2006 to 2010 by the National Center for Health Statistics married black women had almost twice the odds of infertility .
Fact: Black men and black women both have much lower levels of vitamin D
Fact: Women OR men of any race who are low vitamin D have fertility problems
See also VitaminDWiki
Male infertility associated with low vitamin D levels – Dec 2012
IVF 4X more successful for white women with lots of vitamin D – many studies
Reproduction function in males improved by vitamin D – review Aug 2012
Male fertility is improved in many ways by vitamin D – Jan 2014, not page
[tiki-download_file.php?fileId=1756] PDF
78 percent of pregnant immigrants in Sweden had less than 10 ng low vitamin D – Nov 2013