Spinach has been grown in Asia for so many centuries that its origins predate existing records. Even if scholars and spinach experts aren't able to pinpoint the exact birthplace of this vegetable, one thing is certain: If there were an award for lifetime achievement, spinach would definitely be in the running. By the 1400s, spinach had made its way throughout Asia where it became a mainstay of many European menus. Today, it's a multi-faceted green eaten worldwide in everything from casseroles and pasta to soups and salads

• Vegan, Gluten-Free and Kosher, this spinach powder is tested for heavy metals, pesticides and microorganisms

• One cup of cooked fresh spinach contains about one milligram more iron than you'll find in 3 ounces (85 grams) of beef liver, which has long been known for its iron content. And far more than you'd encounter in a head of lettuce. In fact, you'd need to eat the entire head of lettuce to gain just 2.02 milligrams of iron, a fraction of what you'll find in spinach