Building Strong Bones in Children

Building strong bones in childhood is a good start for bone health throughout life. All bone density is built in childhood and teens. Building bones are finished by age 20. Adults, replace old bone with new bone, but slowly.

In adults, bones get weaker over time. The entire human skeleton is replaced every 10 years through the process of bone dissolving and remodeling. When bone build-up lags behind the process of bone breakdown, the individual suffers from lower bone mass or “Osteoporosis”.

3- essential ingredients help keep pace with bone breakdown:

  • Vitamin D
  • Calcium
  • Exercises

Vitamin D:

  • Exists as vitamin-D2 and vitamin-D3
  • On exposure the sunlight enters the skin, causing the transformation of Pro-vitamin-D3 to photo-labile Previtamin-D3. Excess sunlight exposure produces 2-inert products “Lumisterol” and “Tachysterol”, thus no hyper-vitaminosis.
  • Pre-vitamin-D3 is converted to vitamin-D3 and transported to the liver, where it is metabolized into “Calcidiol” and stored. Blood testing for vitamin D reflects both synthesis and intestinal absorption from the diet.
  • Calcitriol made from Calcidiol in both kidneys, helps in calcium absorption from the intestines to build bones.

Factors affecting vitamin-D synthesis:

  • Exposure to sunlight provides the best source of vitamin D. In all seasons, 10 to 15 minutes of sun exposure near midday is enough. A dark-skinned, in winter or resident in northern latitudes, gets enough vitamin D from sun exposure.
  • Cloth-covered body or sun-screen application reduces skin penetration by 95% and limits the production of vitamin D3.
  • Vitamin D helps the body absorb calcium and phosphorus from food, deficiency makes it difficult to maintain their levels in bones and causes rickets.

Absorption is hampered by:

  • Mal-absorption: Celiac disease, pancreatic insufficiency (Cystic Fibrosis)
  • Chronic liver disease
  • Drugs: Rifampisin, Isoziazide, anticonvulsants & corticosteroids
  • Inadequate Nutritional intake
  • Age & physiology: elderly & obese etc.
  • Premature babies spend less time in the womb to receive vitamin D, hence lower vitamin D levels.
  • Decreased stores in pregnancy, deprive breast milk of vitamin D; such babies need oral vitamin D.
  • Low levels are linked with i) Hypertension, ii) Diabetes, iii) Myopathic disorders,  iv) Infection prone, v) Tuberculosis, vi) Auto-immune diseases & vii) Cancers.

Symptoms of Rickets

  • Delayed growth & motor skills
  • Pain in spine, pelvis and legs
  • Muscle weakness
  • Disorders due to low phosphorus levels.
  • Deficiency softens growing tissue at ends of long bones (growth plates) causing skeletal deformities:
  • Osteomalacia co-occurs with rickets; even mineralized bones are weak, causing bowing outwards, seen in lower limbs if the child is walking. Skeletal deformities require corrective surgery.
  • Protrusion of acetabuli causes deformity of hips
  • Knock knee.
  • Prominent costo-chondral junction of chest & lower ribs pulled inwards inferiorly by attachment of diaphragm cause Harrison’s sulcus.
  • Widening of wrists and ankles

Radiographic features of growing ends:

  • Fraying: indistinct margins.
  • splaying: widening
  • cupping: concavity
  • pseudo-fracture on the compression side of the bone
  • Features are prominent in the knee, distal femur, proximal tibia, ulna wrist:     

if untreated, causes Failure to grow, Abnormally curved spine, Bone deformities, Dental defects, and Seizures

Treatment: Vitamin D, Calcium-rich foods, and Exercises

  1. Vitamin D
  • Natural vitamin D-rich foods help calcium absorption. Vitamin D is recommended to all kids, even newborns.
  • Kids should consume Vitamin D rich foods: Fatty fish, Fish Oil, Egg yolk,
  • Vitamin D fortified Foods: Infant formula, Cereal, Bread, Milk, Orange juice.
  • Dose of vitamin D:
  • <1 year: 400 IU /day, >1 year: 600IU/day; maintenance =30ngm/day
  • Those on anticonvulsants, anti-fungal & Gluco-corticoids need 3-4 times for their age.
  • Available: Oral drops 400IU/ml, tablet: 1000-2000 IU & sachet:60,000IU
  1. High-Calcium Foods:
  • Green leafy parts of vegetable store calcium and vitamin K, boosts mineral bone density; collard green, Spinach, Soya bean green, Celery, Mustard Green, Spring Onions, Fenugreek, Cabbage, Broccoli, Cauliflower, Sweet Potatoes.
  • Soya milk, Tofu, Dried Figs, Mushrooms,
  • Almonds, Ground nuts, are high in potassium and inhibit the loss of calcium in the urine.
  • Walnuts, rich in Proteins, Alpha-Linolenic Acid, Omega-3-fatty acids; slows the rate of bone loss & enhance bone formation.
  • Bananas are rich in Potassium, Calcium & Magnesium
  • Prunes, Dried Plums have “inulin” helps calcium absorption
  • Manganese-rich Pineapple and Strawberries tackle free radicals and prevent damage joints, osteoporosis & fracture of bone. Magnesium reduces bone loss and increases bone density. “Bromelain” halts inflammation and damage to joint cartilage.
  • Beans, nuts, seeds, fortified orange juice or cereal.
  • Low-fat dairy product quantity is based on age. Kids need 2–3 servings daily.
  • Encourage a vegetarian diet except Fish: Salmon is rich in Selenium and Omega-3-fatty acid, are anti-inflammatory. Consume 3-5 times a week.
  • Proteins in Meat & Eggs; high in sulfur-containing amino acids, acidifies blood & while neutralizing acid, the bone dissolves into the bloodstream and excreted through the kidneys.
  • Others: genetics, caffeine, salt, tobacco, lack of physical activity.
  • Avoid Soft drinks, Alcohol, Nicotine, Caffeine, Refined sugar & excess salt.
  • Recommended Dietary Allowance (RDA) of calcium:
  • Child 1-9 years = 600mg /day, 10–18 years =800 mg /day
  • Pregnancy & lactation =1200mg /day
  • < 6 years Vitamin-D =400 IU/ day
  • Regular Exercise: walking, running, jumping, and climbing help in building bones, are weight-bearing activities. They use muscle force and gravity to put pressure on bones to build stronger bones.


Dr. U. B. Lall is a practising paediatrician in New Delhi. His practice has spanned over five decades and has retired as the Head of the department, Paediatrics from Moolchand Hospital. He has published various articles in International journals and is a recipient of the prestigious S. T. Achar Award in 1974.