Increase your Vitamin D during the low light months

Being outdoors and getting sunshine is the easiest, most pleasant way of getting Vitamin D, but if that's not an option for you try eating mackerel, salmon and egg yolks, which are all foods with high levels of vitamin D. You can also take a spoonful of cod liver oil, which I'm sure you're running right out to get. Vitamin D has been shown to be important to our overall health and well-being.