Our skeletal system is unique in a way that some of our bones are newly formed only after birth, whereas every other organ forms before birth and only increases in size afterward. Bone has many interesting features, physiological and even historical. Yes, historical; dinosaurs were rediscovered from their bones, human evolution was studied from bone fossils of the cave man, carbon dating of skeletal remains helps identify their era and a lot more! Our bones develop from two different processes, endochondral ossification where a soft cartilage model develops first which is then converted into hard bone, and membranous ossification where the bone originates directly from the precursor mesenchymal cells.
Healthy bones are vital for a dynamic lifestyle and interestingly bone is the most dynamic organ with constant absorption and resorption of minerals including calcium and phosphorus. The philosophy of our bone is “To improve is to change; to be perfect is to change often.”; remodelling of our bones takes place so continuously that in a period of 10 years our entire skeletal system is replaced like new! Any hard structure which provides stability or mobility tends to wear and tear like cracks in the ceiling and rust in the automobile. Bone provides both stability and mobility, and it overcomes these issues by strictly following the philosophy mentioned above. With our day-to-day activity, we all incur some micro fractures which are taken care of by this mechanism of remodelling.
Another philosophy “Positive stress is important for growth!” also holds good for the bone.
Stress from physical activity is essential for bone growth as well as remodelling, and so physical activity is important for growing children and elderly people. Without physical activity, whatever health supplements we take will not be fully utilized for bone growth or strengthening. Apart from structural support, our skeletal system has many other functions including protection of vital organs (skull protecting brain, vertebra - spinal cord, ribs - lungs and heart), production of blood products and storage of minerals.
Bone metabolism is regulated by various hormones including thyroxine, parathormone, growth hormone and insulin, and micro-nutrients including vitamin C, D and K. All of that being said, bone is an architectural wonder of nature and it is our duty to maintain its health for our own well-being. The steps to healthy bones depend on the age of the individual and are listed below:
Children (Why? Because 90% of bone strength is achieved by 18 years of age.)
Physical activity through sports and games should be a daily routine for all children to boost their physical and mental health.
Proper balanced nutrition with emphasis on vegetables, milk and other protein sources.
Ensure adequate calcium and vitamin D intake as per the recommended daily allowance (RDA) for age.
Prevent childhood obesity as it is inversely related to bone density.
Adults (Why? Most productive part of life.)
Avoid smoking and excessive drinking.
Regular physical activity (weight-bearing exercises), at-least one-hour a day and 5 days a week.
Proper posture while working and avoiding prolonged sitting.
An early screening if risk factors for osteoporosis are present (familial history, chronic steroid intake, other metabolic disorders, etc.).
Calcium supplements when indicated like pregnancy and lactating mothers.
Elderly (Why? More susceptible to osteoporosis and fractures.)
Periodic health check-up including bone density scan (DEXA scan).
Calcium and vitamin D supplements are important for women above 60 and men above 70.
Active lifestyle with weight bearing exercises like brisk walking.
Anti-osteoporosis medications when bone density is less or there is history of fracture.