I had a hard time this past winter -- for some reason, my body could not maintain its own temperature. I felt achy and cold; It wasn't a fun time.
After several doctor's appointment, it was determined that I was suffering from both an iron and vitamin D deficiency.
A lot of people don't keep track of their vitamin intake, which is important to do. Vitamins and minerals are essential for body function. While multivitamins are an option, you can also get the recommended dose of vitamins in the food you eat.