BIO (a) The recommended daily allowance (RDA) of the trace metal magnesium is 410 mg/day for males. Express this quantity in µg/day. (b) For adults, the RDA of the amino acid lysine is 12 mg per kg of body weight. How many grams per day should a 75-kg adult receive? (c) A typical multivitamin tablet can contain 2.0 mg of vitamin B2 (riboflavin), and the RDA is 0.0030 g/day. How many such tablets should a person take each day to get the proper amount of this vitamin, if he gets none from other sources? (d) The RDA for the trace element selenium is 0.000070 g/day. Express this dose in mg/day.

Solution 12E Case (a) Given dose to magnesium is 410 mg Convert this to g 3 We know 1 mg is 1 × 10 g And 1 g is 1 × 10 g6 Hence we can write 1 g 410 mg × 10 g 410 × 10 g × 16g 10 g 6 410 × 10 g = 410 g Case (b) Given 12 mg RDA /kg of weight for adult We need to calculate the amount of RDA required for 75 kg adult This can obtained as 12 mg × 75 kg To have both the terms in one unit 6 We shall write using 1mg = 1 × 10 kg 5 1.2 × 10 kg × 75 kg We get 4 9 × 10 kg Or this can written as 900 mg Hence an adult of 75 kg requires 900...