CHENNAI: Nutrition and bone health are closely associated. Poor nutrition leads to suboptimal bone health. Although osteoporosis (weak and brittle bones) and osteomalacia (softening of bones) have complex etiologies, the development of these diseases can be minimised by providing adequate amounts of nutrients throughout the lifecycle.
With the right kind of dietary intake and exercise, the reduction in bone density and in turn development of osteoporosis can be prevented. Calcium, vitamin D, protein and vitamin K are nutrients for optimal bone health and present a preventive role against bone diseases.
Calcium: Calcium is the major building block of the bone. It is a myth that calcium supplements are better than the calcium absorbed from food (dietary calcium). The bioavailability of calcium from milk is highest and greater than from supplements. Milk and dietary calcium work better for balancing calcium needs. In the case of lactose intolerance, the degree of lactose intolerance varies in individuals. Enzymes such as lactaid and maxilact are available, which digest 90% of lactose in milk. Some tolerate fermented and cooked milk products, like buttermilk, curds, custards, and cottage cheese or when mixed with cereals or cocoa for better tolerance. Some tolerate up to 200ml of milk a day.
Food sources: Milk, paneer, ragi, agathi leaves, drumstick leaves, and soya.Vitamin D: Vitamin D is required for optimal calcium absorption. Calcium and vitamin D go hand in hand. Vitamin D synthesis takes place in the skin when it is exposed to sunlight, especially ultraviolet B rays. In children and adults, sunlight exposure to the skin of hands, forearms and face for 10 to 15 minutes is sufficient to produce vitamin D depending on the time of the day of exposure. For the elderly, however, given that they may spend more time indoors, vitamin D supplements may be necessary.
Food sources: Oily fish like salmon, sardines, mushrooms, eggs, liver, and in some countries, fortified foods.
Protein: Adequate protein intake during growth is important for optimal growth and development. During adulthood, it is important to maintain and later avoid the decline in bone density. Lack of protein affects muscle strength and increases the risk of falls and fractures.
Food sources: Pulses, whole grams, soya, eggs, milk and milk products, chicken, and fish.
Vitamin K: In addition to its role in blood clotting, it plays a role in bone health as well. Vitamin K activates proteins involved in bone formation and the mineralisation process that makes bones strong. Osteocalcin, a bone-specific protein made by osteoblasts, requires vitamin K for maturation. Vitamin K comes in two forms. Vitamin K2 has a more protective effect on bone than vitamin K1. However, deficiencies of both K1 and K2 appear to have a negative effect.
Food sources: Green leafy vegetables, cabbage, lettuce, cauliflower, eggs, and chicken breast.
Other nutrients: Adequate intake of fruits and vegetables has been shown to reduce the risk of loss of bone density due to multiple vitamins and minerals present in fruits and vegetables. Other nutrients that have protective effects on bone density are vitamin B6, vitamin B12, vitamin A, magnesium, phosphorous, manganese, boron, copper, and zinc. Isoflavones in soy are estrogen agonists and antioxidants in bone cells. Isoflavones stimulate osteoblastic bone formation and inhibit osteoclast bone resorption.
Exercise: Exercise regularly especially weight-bearing activity and muscle-strengthening exercise promises to be protective against muscle and bone loss. Exercise helps in bone-building during childhood and maintains bone during adulthood and later in life.
What to avoid
A healthy diet that includes adequate consumption of calcium, vitamin D and protein is more effective for bone health maintenance than vitamins and other supplements.