3. The figure below'shows the amounts of certain nutrients present in a helping of cereal with milk. Each value is expressed as the percentage of an adult's daily requirement of each nutrient. The amount provided by cereals is shown separately from the amount provided by milk. % of daily requirement 100 90 70 9 50 40- 30 20 0 % provided by cereal % provided by milk energyproteinfat vit vit niacinvit vit vit iron calcium B1 B2 B12 D A Nutrients in a helping of cercals and milk (a) What is shown by the fact that the column for vitamin D is completely shaded while the column for calcium is unshaded?
