I buy these for the men in my family along with Adam Now multis and Omegavia fish oil pills. Black men have notoriously low levels of Vitamin D unless they work in the sun. My brother has problems with Insomnia and anxiety and this (along with Calm Magnesium) helps him sleep better and have more energy in the daytime. He stopped after his D levels tested normal and reverted back to the same issues. He then tried a cheaper brand which didn't help. This is now a staple. I read that most people are deficient (especially the elderly, obese, Crohn's and Celiac sufferers) so there was no reason to stop. My ex is fit and healthy but he would be tired and cranky with low T. These helped him along with a prescription he was taking. So the verdict is in, they highly recommend