For a few years the skeleton and the blood supply are both being built at once — and calcium and iron requirements climb to their steepest point of the lifespan. Slide through the ages, then build meals and calculate how much actually gets absorbed.
Requirements across the growth spurt
The growth spurtmove the age slider
—Calcium RDA
—Iron RDA
—cm / year
—mg bone Ca/d
What the chart is showing
Height velocity is a smoothed reference curve, not any one person's growth. The shaded band marks the fastest-growing years. Watch how the calcium and iron steps sit underneath it.