Leafy green vegetables

Leafy green vegetables such as spinach, kale, chard, collard greens, and beet greens are among the world's healthiest foods. They're high in fiber, water, vitamin C, vitamin A, iron, antioxidants, phosphorus, and nitrates, all of which help to improve circulation and potentially decrease blood pressure

Many leafy green vegetables are high in calcium. For example, 1 cup (190 grams) of cooked collard greens has 268 mg of calcium or roughly 21% of the daily need. It's worth noting that some varieties, like spinach, are high in oxalates, which are naturally occurring compounds that bind to calcium and prevent it from being absorbed. As a result, despite its high calcium content, spinach is not as effectively absorbed as other calcium-rich greens with low oxalates, such as kale and collard greens.