Vitamins and the chemistry behind them

In this series of activities, students learn about a range of chemical ideas while investigating vitamins and vitamin supplements. Designed for 11–16 year olds, the resources give students the opportunity to conduct practical experiments, evaluate evidence for claims made about vitamins and engage with a variety of scientific and historical contexts. Stimulate your students to explore:

• The link between vitamin C and scurvy
• The structure and properties of vitamin C and how to test for it
• How vitamins were discovered
• Evidence for vitamin C preventing colds
• Whether vitamin supplements are effective

Each activity includes instructions for students, as well as editable worksheets and resources available for download.

1. Vitamin C and scurvy

Summary

In this directed activity related to text (DART), students read about the effects of scurvy, its historical prevalence among sailors and the discovery of a link between scurvy and vitamin C. The core of the activity is an extract from James Lind’s ’Of the Prevention of the Scurvy’, in which the Royal Navy surgeon describes an experiment conducted in 1747 to compare treatments for the disease.

After reading both texts, students answer a series of questions to check and consolidate their understanding, before considering how Lind could have improved his experiment and whether his conclusion was correct.

2. Testing for vitamin C

Summary

Students conduct a practical experiment to compare the amounts of vitamin C in different fruit juices using a simple test with iodine solution. They then answer questions to reflect on what they have found out and compare their results with the labels on the fruit juice packaging.

The ‘Testing for vitamin C’ worksheet includes extension questions which relate the experiment to the DART, ’Vitamin C and scurvy’, as well as suggestions for further investigations to find out more about vitamin C.

An additional handout, ‘Did you know about vitamin C?’, provides further information about the chemical structure of vitamin C and how it used by the body.

3. Catching a cold?

Summary

In this activity, students investigate the familiar claim that vitamin C helps to prevent or treat colds. They read about the work of Linus Pauling during the 1970s and evaluate the data he used to support this claim, identifying weaknesses in the original study and assessing how these might impact the conclusions we can draw from it.

An additional handout, ‘Did you know about Linus Pauling?’, provides background information about Pauling’s life and work.

4. A cold survey

Summary

Students carry out a survey to determine whether vitamin C might help prevent colds. After answering the survey for themselves, students collate responses from the rest of the class, as well as responses collected from family and friends if there is sufficient time. They then work through a series of questions to analyse their results, identifying any patterns and drawing conclusions based on the available evidence.

5. Are vitamins a waste of money?

Summary

Students work in groups to consider a range of views on vitamins pills and supplements. They rank four statements according to how strongly they agree with them, and provide reasons for their rankings, before presenting their decisions to the rest of the class. Together, students agree an answer to the question, ‘Are vitamins a waste of money?’, giving evidence in support.

An additional handout, ‘Did you know about Casimir Funk?’, introduces students to the scientist credited with the discovery of vitamins.

6. Key words

Summary

This handout provides information about terms relating to vitamins and the contexts used for these activities. Key words include ‘clinical trial’, ‘deficiency disease’, ‘double blind’, ‘placebo’, ‘RDI or RDA’ and ‘vitamins’.