HUMN NTR 2410 Vitamin C (500 mg) Experimental Protocol

HUMN NTR 2410 Vitamin C (500 mg) Experimental Protocol

Preparation Day
Once again, on the day before your 500-mg vitamin C experiment, avoid foods and beverages that are
high in vitamin C and dietary supplements that contain vitamin C. Below is a list of fruits and vegetables
that are naturally high in vitamin C, as well as some packaged foods that may have vitamin C added to
them.
Fruits that are high in vitamin C
• Berries (e.g., strawberries, raspberries, blueberries, cranberries)
• Cantaloupe
• Citrus fruits and juices (e.g., orange, grapefruit)
• Kiwi fruit
• Mango
• Papaya
• Pineapple
• Watermelon
Vegetables that are high in vitamin C
• Bell peppers (green, red, yellow)
• Cruciferous vegetables (e.g., broccoli, Brussels sprouts, cauliflower)
• Leafy green vegetables (e.g., spinach, cabbage, turnip greens)
• Potatoes (e.g., sweet potatoes, yams, white potatoes)
• Tomatoes and tomato juice
• Winter squash
Packaged foods that may be high in vitamin C (look for vitamin C or ascorbic acid in the list of
ingredients)
• Fortified breakfast cereals
• Meal replacement bars/ shakes
• Sports nutrition products
Other than avoiding rich sources of vitamin C, there are no restrictions on food intake, fluid intake, or
exercise on the day before your vitamin C experiment.
It may be helpful to assemble all the supplies you’ll need before you go to bed the night before you
conduct your experiment. Set a notification on your phone to remind yourself to start your experiment
shortly after you wake up.
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Vitamin C Experiment Day (500 mg)
Before starting the first of these two experiments, gather all the items listed below. Some have been
provided as part of your Nutrition Lab Kit; others must be procured from your household.
Items Included in Nutrition Lab Kit: Other Items You Will Need:
• 1 vitamin C tablet (500 mg)
• 4 urine test strips (you MUST label these)
• 4 cups of bottled or tap water (for drinking)
• 1 disposable plastic cup (for urine collection)
• Dish soap
• 5 clean paper towels
• Vitamin C Results Reporting Form (download
this from Carmen)
• Waterproof marker
• Timer (e.g., cell phone)
• Camera (e.g., cell phone)
In this experiment (the second of two), you will observe urinary excretion of vitamin C over a 6-hour
period. At the start of this 6-hour experiment, you will consume a 500-mg vitamin C tablet. You can eat
and drink throughout the experiment, but avoid foods and beverages that are high in vitamin C and
refrain from taking any other dietary supplements containing vitamin C or consuming foods that are
highly fortified with vitamin C. You will collect urine samples at baseline (0 hours) and 2, 4, and 6 hours
after taking the dose of vitamin C and test vitamin C content of the urine samples.
The timeline below summarizes the experimental procedure.
This timeline uses 8:00 AM as the baseline, but you can adjust the start time to fit your schedule. Please
be sure to record the times of your samples.
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STEP 1: Label all your test strips.
As you did for Part 2, label the blank end of each of the four strips using a waterproof marker (e.g.,
Sharpie) before you begin your experiment:
0 = baseline
2 = 2 hours
4 = 4 hours
6 = 6 hours
NOTE: If your strips are not labeled with a marker as described above, you will lose 0.5 point per
sample.
STEP 2: Flush your first morning void.
After you wake up on the morning of the experiment, discard (i.e., flush) your first morning void of
urine. The first void of the day is likely to contain metabolites and wastes from the previous day. We will
not test this first urine of the day.
STEP 3: Hydrate!
Over the next 30 to 60 minutes, drink about 1/2 cup of water to stimulate urine production.
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STEP 4: Collect and test your baseline urine sample
For each urine sample collection, you will need a disposable plastic cup, one test strip, and a paper
towel.
The test strips are designed to measure many different compounds in your urine. For this experiment,
we are only interested in the bottom square on the test strip, which is used to measure vitamin C. Note
the color of the vitamin C square before your start the experiment (it may vary slightly from the image
shown below).
As soon as you are able to produce a fresh urine sample, collect your urine sample in the plastic cup.
This is your baseline (0 hours) urine sample. Get a timer ready to count down 30 seconds. Holding the
labeled end of the test strip between your thumb and forefinger, dip the test strip in the urine sample
for a few seconds so that all the colored squares become saturated with urine. If the urine sample is too
shallow to submerge all the colored squares on the strip, you can tilt the cup slightly to one side or bend
the strip inside the cup, as pictured below.
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Remove the test strip from the urine sample and place it on a dry surface (e.g., on a paper towel on the
edge of the bathroom sink).
Start your 30-second timer and allow the test strip to develop. After 30 seconds, observe the color of
the test strip, take a photo of it, and record the time and your observation in the Vitamin C Results
Reporting Form (see Materials, above). The reporting form is an Excel file that will automatically chart
your results. Be sure to record the time of your sample in Column A, then mark an “X” in the cell that
corresponds to your observation.
NOTE: If you think your strip appears to be a shade of green between two of the colors pictured above,
choose the lower value. For example, if your strip appears to be a shade of green between 0 mg/dL
(neg) and 20 mg/dL, mark 0 mg/dL on your reporting form.
After you have recorded your results, flush the urine sample down the toilet, discard the used test strip
in the waste basket, and wash out the plastic cup with soap and water so it will be ready to collect your
next urine sample.
In Nutrition Lab: Vitamin C, Part 3, upload a photo of your labeled and developed 0-hour (baseline)
urine test strip.
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STEP 5: Consume the 500-milligram vitamin C tablet.
Within a few minutes of collecting and analyzing your baseline urine sample, chew and swallow your
500-milligram vitamin C tablet. The vitamin C tablet is chewable and tastes sweet.
Then, set your timer for 2 hours.
STEP 6: Hydrate!
Over the next two hours, drink ~1 cup of water to stimulate more urine production.
NOTE: It is okay to consume other beverages (e.g., coffee) besides water, but avoid fruit juice or other
beverages that contain vitamin C.
STEP 7: Collect and test your 2-hour urine sample.
When your timer alerts you, collect your 2-hour urine sample in the disposable plastic cup. Following the
procedure outlined in STEP 4, dip your test strip (labeled “2”) in the urine sample, allow it to develop for
30 seconds, then observe your results. Take a photo of the test strip and record your 2-hour observation
on the Vitamin C Results Reporting Form. Flush the urine sample, discard the used test strip, and wash
the plastic cup.
Set your timer again for 2 hours.
In Nutrition Lab: Vitamin C, Part 3, upload a photo of your labeled and developed 2-hour urine test strip.
STEP 8: Hydrate!
Over the next two hours, drink ~1 cup of water to stimulate more urine production.
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STEP 9: Collect and test your 4-hour urine sample.
When your timer goes off, collect your 4-hour urine sample in the disposable plastic cup. Following the
procedure outlined in STEP 4, dip your test strip (labeled “4”) in the urine sample, allow it to develop for
30 seconds, then observe your results. Take a photo of the test strip and record your 4-hour observation
on the Vitamin C Results Reporting Form. Flush the urine sample, discard the used test strip, and wash
the plastic cup.
Set your timer again for 2 hours.
In Nutrition Lab: Vitamin C, Part 3, upload a photo of your labeled and developed 4-hour urine test strip.
STEP 10: Hydrate!
Throughout the next two hours, drink 1 cup of water to stimulate more urine production.
STEP 11: Collect and test your 6-hour urine sample.
When your timer alerts you, collect your 6-hour urine sample in the disposable plastic cup. Following the
procedure outlined in STEP 4, dip your test strip (labeled “6”) in the urine sample, allow it to develop for
30 seconds, then observe your results. Take a photo of the test strip and record your 6-hour observation
on the Vitamin C Results Reporting Form. Flush the urine sample, discard the used test strip, and wash
the plastic cup.
In Nutrition Lab: Vitamin C, Part 3, upload a photo of your labeled and developed 6-hour urine test strip.
STEP 12: Upload your Results Reporting Form
Upload your fully completed Vitamin C Results Reporting Form. A blank reporting form is available in
the Other Items You Will Need section of the instructions (above), but ideally, you should add the results
of your 500-mg vitamin C experiment to the same reporting form you used for Nutrition Lab: Vitamin C,
Part 2 when you reported the results of your 100-mg vitamin C experiment.
NOTES: To ensure you receive proper credit for this item, your Vitamin C Results Reporting Form should
be saved in Excel format. Be sure to enter the time you collected each sample in Column A of the
reporting form. For each sample, mark your results with an “X” in the cell that corresponds to your
observation, and Excel will automatically chart your results. Save the file with your data before you
upload the file to Carmen.