The typical dietary contribution of calcium and magnesium is over 80% of the total
daily intake. Of this, approximately 30% of calcium and 35% of magnesium will be
absorbed. The bioavailabilities of calcium and magnesium from milk and water are on
the order of 50% (Ong, Grandjean & Heaney, 2009). For calcium and magnesium, the
typical contribution from water is 5–20% (WHO, 1973; National Research Council,
1977; Neri & Johansen, 1978).