Chapter U4.7, Problem 5E

(a)

Interpretation Introduction

Interpretation:

The milligrams of vitamin A that would be lethal to a 132 lb adult given that LD50 for vitamin A is 1510 mg/kg needs to be calculated.

Concept Introduction:

A lethal dose of a substance is given by LD₅₀ which is the amount of substance that kills 50% of a target sample.

Answer to Problem 5E

90600 mg.

Explanation of Solution

Given:

LD₅₀ for vitamin A = 1510 mg/kg

Weight of adult = 132 lb

Calculation:

Step 1: Convert 132 lb to kg

1 kg = 2.2 lb

  $\text{Weight of adult in kg = }\frac{132\text{ lb}\times \text{1 kg}}{2.2\text{ lb}}=60\text{ kg}$

Step 2: Calculate the mg of vitamin A

  $\begin{array}{c}\text{Vitamin A lethal dose = }\frac{1510\text{ mg}\times \text{60 kg}}{1\text{ kg}}\end{array}$

            $\begin{array}{c}=90,600\text{ mg}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The number of tablets each containing 0.40 mg of vitamin A that would be lethal to a 132 lb adult needs to be calculated.

Concept Introduction:

A lethal dose of a substance is given by LD₅₀ which is the amount of substance that kills 50% of a target sample.

Answer to Problem 5E

Number of vitamin A tablets = 226,500

Explanation of Solution

Given:

Weight of adult = 132 lb

Amount of vitamin A per tablet = 0.40 mg

Calculation:

From part (a):

A lethal dose of vitamin A for an adult = 90600 mg

  $\begin{array}{c}\text{Number of vitamin A tablets = }\frac{\text{Lethal dose}}{\text{vitamin A/tablet}}\end{array}$

          $\begin{array}{c}\frac{90600\text{ mg}}{0.40\text{ mg/glass}}=226,500\text{ tablets}\end{array}$

               $\begin{array}{c}=226,500\text{ tablets}\end{array}$

(c)

Interpretation Introduction

Interpretation:

The benefits of vitamin A need to be explained.

Concept Introduction: All the vitamin types are essential for human health, but there is a limit for each vitamin in our body. The deficiency and excess of all types of vitaminsare dangerous for health.

Explanation of Solution

Vitamin A is good for health as it protects the eyes from age-related effects or night blindness. It may also lower the risk of cancer. It supports a healthy immune system, promotes growth and healthy reproduction, and also strengthens bones.