How much more milk would a typical adult have to drink to get their RDA for calcium compared with the amount of milk needed to get their RDA for vitamin B-12? ================================== For calcium, the RDA is 1000 mg - AQA - GCSE Biology - Question 7 - 2018 - Paper 1

1. Calculate the volume of milk needed for calcium:

   • RDA for calcium: 1000 mg
   • From Table 8: 500 cm³ of milk contains 605 mg of calcium.

   $\text{Volume of milk for calcium} = \frac{1000\text{ mg}}{605\text{ mg per } 500\text{ cm}^{3}} \times 500\text{ cm}^{3} = 826.4\text{ cm}^{3}$

2. Calculate the volume of milk needed for Vitamin B-12:

   • RDA for vitamin B-12: 2.4 µg
   • From Table 8: 500 cm³ of milk contains 4.5 µg.

   $\text{Volume of milk for vitamin B-12} = \frac{2.4\mu g}{4.5\mu g} \times 500\text{ cm}^{3} = 266.67\text{ cm}^{3}$

3. Calculate the extra volume of milk required for calcium:

   • $\text{Difference} = 826.4\text{ cm}^{3} - 266.67\text{ cm}^{3} = 559.73\text{ cm}^{3}$

Thus, a typical adult would need to drink approximately 559.73 cm³ more milk to meet the calcium RDA.