Combined Nutrient Effects: Does supplemental vitamin C intake amount and vitamin D status have a combined effect on the flu among GrassrootsHealth participants?

Published on January 9, 2020

In an earlier post we showed that 38% fewer GrassrootsHealth participants who reported taking at least 1,000 mg/day of supplemental vitamin C experienced the flu compared to those who reported no supplemental vitamin C intake. Today, we’ll explore how vitamin D status may impact this association between supplemental vitamin C intake amount and the flu.

Using the data you provided for the GrassrootsHealth study, we found that the percent of participants who experienced the flu in the prior 6 months was 55% lower for those with a vitamin D level at or above 40 ng/ml who also reported taking 1,000 mg/day or more of supplemental vitamin C compared to those with a vitamin D level below 40 ng/ml who reported no supplemental vitamin C intake.

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This preliminary analysis suggests that the combined effect of both maintaining a vitamin D status of at least 40 ng/ml and taking at least 1,000 mg/day of supplemental vitamin C could provide greater risk reduction for the flu than having a vitamin D status less than 40 ng/ml and not taking supplemental vitamin C. Further analysis is needed to assess this association by adjusting for other biometric and lifestyle risk factors. These analyses of individual and combined nutrient effects from GrassrootsHealth are possible because YOU provide us with data on multiple nutrients and health outcomes.

Vitamin D, omega-3s, magnesium, and other nutrients are important to measure!

Make sure you know your vitamin D level, and take steps to keep it within a target of 40-60 ng/ml or 100-150 nmol/L! Through GrassrootsHealth Nutrient Research Institute, you can also test your essential elements magnesium, copper, zinc and selenium, toxins such as lead, mercury and cadmium, as well as your omega-3 levels, inflammation levels and thyroid stimulating hormone (TSH) level. Find out your levels today! Log on to the test selection page (click the link below) to get your tests and see for yourself if your levels can be improved.

Make sure you track your results before and after, about every 6 months!

Click Here to Access the Test Page

How can I track my nutrient intake and levels over time?

To help you track your supplement use and nutrient levels, GrassrootsHealth has created an online tracking system called myData-myAnswers. For each specific supplement, you can track what days you take it, how much, and many other details. This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels. Check it out today!

How Can You Use this Information for YOUR Health?

Having and maintaining healthy vitamin D and other nutrient levels can help improve your health now and for your future. Measuring is the only way to make sure you are getting enough!

STEP 1 Order your at-home blood spot test kit to measure vitamin D and other nutrients of concern to you, such as omega-3s, magnesium, essential and toxic elements (zinc, copper, selenium, lead, cadmium, mercury); include hsCRP as a marker of inflammation or HbA1c for blood sugar health

STEP 2 Answer the online questionnaire as part of the GrassrootsHealth study

STEP 3 Using our educational materials and tools (such as our dose calculators), assess your results to determine if you are in your desired target range or if actions should be taken to get there

STEP 4 After 3-6 months of implementing your changes, re-test to see if you have achieved your target level(s)

Enroll in D*action and Build Your Custom Test Kit!