Know your veggies: Cucumbers. Consisting mostly of water, and containing electrolytes, cucumbers can help prevent dehydration. One cup of cucumber provides 8.5 micrograms (mcg) of vitamin K. The Office of Dietary Supplements (ODS) recommends that women aged 19 years and over consume 90 mcg of vitamin K each day, and men 120 mcg. They also contains calcium. Vitamin K helps improve calcium absorption. Together, these nutrients contribute to good bone health. Cucumbers are a good source of fiber, and they contain potassium and magnesium. They also have a low score on the glycemic index (GI), which means they provide important nutrients without adding carbohydrates that can increase blood glucose. Now you know how good cucumbers really are!