SPINACH OR PALAK REDUCE ITS  QUANTITY  WHEN IT GETS COOKED, WHY?

Most vitamins are sensitive to heat and water. Water-soluble vitamins, especially most of the B vitamins and vitamin C, leach into cooking water. Vitamins A, D and E are fat-soluble and leach into cooking oils. Vitamin C is the most likely to get lost in cooking, according to Scientific American. It's susceptible to heat, air and water. Other vitamins that cooking may degrade include B-6, which is susceptible to heat, air and water; and E, which is sensitive to heat, air and fat. Only two vitamins, K and B-3, or niacin, are stable enough to hold up well during cooking.