Dr. Dharmakanta Kumbhakar
Bones are the living tissues that form the major portion of our skeleton. There are 206 bones in the body of an adult human being whereas infants have around 300 bones in their body. Bones help us in mobility and protect our internal organs. They also serve as a bank for important minerals, such as calcium, which help support numerous organs in our body.
Bones are made up of proteins and other minerals like calcium, phosphate and magnesium. Collagen (a protein), which is a cementing substance, forms the structure and framework of bones. The thin membrane that covers the outer surface of a bone is called Periosteum. It consists of nerves and blood vessels. The outer layer of a bone which is very dense is compact bone. When we look at a skeleton, the compact bone is what we see. The cancellous bone layer, which looks like a sponge and is not as hard as the compact bone covers the bone marrow which is the innermost part of our bone.
Bones continuously keep undergoing a vigorous process of resorption (removal of old bone) and deposition (formation of new bone) known as bone metabolism throughout life. In adults, the entire skeleton is completely replaced every 7–10 years. Osteoblasts are cells that are responsible for the formation of new bones and osteoclasts are cells that are responsible for the breaking down of bones. It is with the co-operation of these cells that our body maintains proper balance of minerals required for our body’s physiological functions.
There are various factors that affect bone health. They are:
- Genetics: Bone disorders can run in the family. If parents or siblings have had bone problems, offspring are more likely to get it. Certain ethnic groups have comparatively stronger bones than other ethnic groups.
- Diet: Adequate calcium and Vitamin D is required for healthy bones. Cigarette smoking, excessive caffeine intake and excessive alcohol intake increase the risk of bone loss.
- Physical activity: Regular exercises and physical activity strengthen our bones.
- Age: Though bones go through a constant state of bone loss and re-growth; as we age, more bone loss than bone growth can occur which is a normal and natural process. So the strength of our bones decreases with age.
- Hormones: Women are more likely to develop bone problems such as osteoporosis. The production of the hormone estrogen is vital in adolescent females and young women so as to maintain bone mass. A shortage of estrogen occurs in these conditions (absence of periods, infrequent menstrual cycles, delay in the onset of the first period and early menopause), affecting bone mass and could lead to osteoporosis.
- Body size: Thin and underweight persons tend to have weaker bones.
Bones are so important that it is vital to keep our bones healthy throughout our lives. Healthy bones provide a strong foundation, allowing mobility and protection from injury. Bone disorders can affect the quality of life. The development of strong bones begins early in life. Taking care of bones by proper nourishment with a calcium and Vitamin D rich diet; and regular physical exercise when we are still young will help us to attain good bones helping us to live the life that we love. Intake of adequate calcium is necessary to maintain healthy bones and to reach the highest level of bone strength since our bone contains 99% of the calcium present in our body. Foods that are rich in calcium are milk and dairy products.
Vitamin D serves many important functions in relation to calcium metabolism. It helps to increase calcium absorption from the gastrointestinal system and kidney; and thereby make it available to our body tissues. Sunlight, which is absorbed by our skin, provides our body with enough vitamin D. It can also be obtained through dietary sources such as fortified milk, vitamin D-fortified foods and fatty fish. Regular exercise can help prevent bone loss and allows us to maintain muscle strength, coordination and balance, which in turn helps to prevent falls and related fractures and provide a lot of relief in some chronic conditions such as osteoarthritis and osteoporosis.