With your diet being nearly the same, if you check you cholesterol levels during rainy season and summer season (in India); you may notice it to be higher during rains. Any guesses why. Cholesterol is a vital component of our body. It is required to make and maintain cell membranes, helps brain to send messages and assists the immune system in defending us. It also is a key ingredient in manufacture of various hormones like estrogens and testosterone. It also is the essential component in our manufacture of vitamin D. Unfortunately excess levels of cholesterols can clog arteries causing life threatening complications. Like a plant which photosynthesises sunlight into sugars, our body converts cholesterol to vitamin D when exposed to the right kind of sunlight. The sunlight necessary for this process is ultraviolet B or UVB. This is strongest when the sun is directly above us, that is more or less during noon. During rains, most of the days are cloudy and severely limit the amount of sunlight reaching us. Also to keep ourselves dry we spend a lot of time indoors or cover our entire body with raincoat or shield ourselves with an umbrella. All these actions reduce the amount of cholesterol that is being converted into vitamin D and thus keeps our test result elevated. What did you learn from this? To keep cholesterol levels in check, other than a healthy diet, get yourself lots of wholesome sunshine. A lifetime of outdoor activity is more fun than a lifetime of liver damaging statins.