article_snippet: Vitamin D is the key to strengthening the immune system,' said Sheila Zhou. '
article_snippet: If you have a sufficient storage of Vitamin D through Summer then Vitamin D should last 30 to 60 days through the colder, darker months.'
article_snippet: Vitamin D is vital for many areas of health including the absorption of calcium, preventing osteoporosis and regulating various cells in the immune system.
article_snippet: Did you know that just 20 minutes of sunlight each day significantly boosts the production of vitamin D in your body?
article_snippet: Vitamin D not only helps protect your body in maintaining healthy immune function, but Vitamin D also assists in general wellbeing.
article_snippet: Unfortunately, with the days getting shorter and the daylight hours diminishing, winter can be a difficult time to get the necessary sunshine, so supplements such as USANA's Vitamin D can be beneficial.
article_snippet: There are amounts of vitamin D in what we eat, but not nearly enough to rely on those foods alone.'
highlights_snippet: Vitamin D from the sunshine is one of the best ways to boost immune system .
  