Fall’s time change is a great but gloomy time of year. The great part? You get an extra hour’s sleep when Daylight Saving ends in November. Put another way: There goes the sun, here comes the Great Winter Vitamin D Deficiency. Even in summer, few North Americans get enough sun to activate your skin’s vitamin D3 factory for long (why it’s called the “sunshine vitamin”). In winter, vitamin D deficiencies are way worse. The sun’s rays are too wimpy to have much effect. Yet D3 (vitamin D’s most active form) is essential. It protects you from brittle bones, hypertension, heart attacks, strokes, diabetes, certain cancers, and more — as if this list isn’t plenty important enough. Vitamin D even perks up your memory. Click here for some easy ways to help stock up on this important vitamin.