More and more evidence is accumulating, documenting the importance of sufficient vitamin D. The research reviewed here evaluated vitamin D levels in men and women aged 65 years and older as it related to depression (Milaneschi Y, et al. 2010). Depressive symptoms were assessed at the start of the study and at 3- and 6- years follow ups. The results showed that low vitamin D levels in both men and women increased the risk of developing depression. The association was even stronger in women than in men. The study population was based in Tuscany, Italy which is not that far north, they are exposed to a fair amount of sunshine. It is also quite common to find less than optimal vitamin D levels even in people from Southern California. The best insurance is to take between 1000 IU to 2000 IU of vitamin D3 daily.