Vitamin D and Fertility

​So I thought this article was pretty interesting. 3 months ago my husband lost 15 pounds in 2 months, but wasn't actually trying to loose wait. We went to the doctor and the only thing that was abnormal was his vitamin D level. Thankfully nothing else was wrong and he was able to gain the weight back within a month by eating more. 
​He has been taking a vitamin D supplement  for the past 3 months. After reading this article I'm wondering if his low vitamin d level has affected our fertility. We have only been ttc for 3 months, but it still makes me wonder. We are both healthy and have no medical problems ... Definitely think we will both be taking multi vitamins now :) 
​Has anyone else seen research out there about vitamin d and fertility?