Published on June 9, 2021

CRP, a biomarker for inflammation linked to many diseases, can be greatly influenced by nutrients including vitamin D, omega-3s, and magnesium

Chronic, low-level inflammation has been linked to a number of chronic diseases ranging from cardiovascular disease and diabetes to mental health disorders and cancer. The higher the inflammation levels, the higher the risk of developing chronic disease.

Sometimes an individual will experience symptoms such as pain or fatigue due to inflammation, but often times there will be no symptoms until disease occurs. However, certain markers exist in the blood that can be measured as an indicator of chronic inflammation – one of the most important being C-reactive protein (CRP).

What is C-reactive Protein?

CRP is a protein produced by the liver in response to a very broad range of causes, such as infection from hepatitis and cancer. Elevated CRP levels have been linked to metabolic syndrome, future heart attacks, stoke, peripheral arterial disease, and the development of diabetes. CRP has been used for decades as a general marker of inflammation that can be measured in your blood. Included as an optional addition to the home blood spot tests offered by GrassrootsHealth, the CRP test uses a high sensitivity assay, hs-CRP where “hs” means high sensitivity, to detect small elevations in CRP. Evidence suggests that levels below 1.0 mg/L indicate low risk of cardiovascular disease, levels between 1.0 and 3.0 mg/L indicate average risk, and levels between 3.1 and 10 mg/L indicate increased risk (levels above 10 mg/L most likely indicate an acute infection or injury). Lifestyle changes such as increasing exercise, losing weight, and quitting smoking can lower CRP levels in the long term.

Nutrient Intake and Status can Greatly Affect Inflammation and CRP Levels

Studies have also associated CRP levels with the intake and status of specific nutrients, including vitamin D, omega-3s, and magnesium. For example, a study by Yang et al. highlighted the relationship between CRP and vitamin D levels in 24 different diseases. The authors discovered a negative association between CRP and vitamin D levels overall, with higher levels of vitamin D associated with lower levels of CRP. The strength of associations varied among diseases, with a steady linear relationship for some (such as respiratory, gastrointestinal, and mental diseases), and a non-linear relationship for others (such as diabetes and cancer), meaning the effect of vitamin D on CRP levels was greater at lower levels but slowed at higher levels of vitamin D, with an eventual plateau. Cancer had a higher cut-off value of vitamin D than other diseases, meaning that after other diseases reached a plateau with vitamin D, cancer still showed a reduced risk from higher levels.

The table below further outlines the association between CRP and vitamin D among the 24 different diseases. Diseases in bold are those that had a statistically significant relationship between vitamin D and CRP levels.

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Cardiovascular Disease (CVD), CRP, and Vitamin D

Inflammation is a risk factor for heart disease and stroke much the same as factors like smoking, high blood pressure and high blood triglycerides increase risk. A series of studies have shown that CRP is a better predictor of cardiovascular risk than other blood tests such as cholesterol. CRP levels can be used by your doctor to assess your risk of developing coronary artery disease and heart attack. In fact, measuring CRP allows doctors to predict your risk of having a heart attack over the next 5 to 10 years if you have risk factors for heart disease.

Results from a study assessing the association between CRP, vitamin D levels and CVD found that participants with vitamin D levels less than 10 ng/ml (25 nmol/L) had a 90% increased risk of CVD compared to those with levels at or above 30 ng/ml (75 nmol/L). Also, those with CRP levels at 0.2 mg/dL or higher had a 47% increased risk of CVD compared to those with levels less than 0.2 mg/dL. The chart below shows that when both vitamin D and CRP are considered together, participants with vitamin D levels below 20 ng/ml and CRP levels at or above 0.2 mg/dL had twice the risk of CVD compared to participants with vitamin D levels at or above 20 ng/ml and CRP levels less than 0.2 mg/dL.

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In a separate analysis, when the association between vitamin D and CVD was assessed for those with CRP at or above versus below 0.2 mg/dL, a significant association was only observed for the higher CRP group. These findings indicate that improving vitamin D status is particularly important in relation to CVD risk for those with higher CRP levels.

Are Omega-3s Comparable to Statins for Heart Health?

Omega-3 fatty acids are also well known to provide healthful benefits for the heart, reduce inflammation and reduce the risk of death.

A study by Kelley et al. investigated the effects of supplementation with 3 grams per day of DHA on levels of inflammation in men with high blood lipid levels in comparison with those receiving placebo (olive oil) over 3 months. Those receiving the DHA had significantly lower levels of several markers of inflammation (including CRP and IL-6) after 3 months than the placebo group, with a 15% reduction in CRP levels at 90 days. Of note, the reduction in CRP concentrations found in this study was comparable to the 15-25% reduction in CRP caused by statins (the frontline pharmaceuticals used to prevent heart attacks and stroke) without any of the adverse effects.

Cancer Risk, CRP, and Magnesium

CRP has been associated with the risk of certain cancers, such as colorectal cancer, lung cancer, and breast cancer. According to Huang et al., chronic low-grade inflammation is linked to the development of approximately 20% of all cancers. These authors looked at magnesium intake and the risk of breast cancer and found a significant inverse relationship, with higher intakes being associated with lower risk. Overall, there was a 22% reduction in breast cancer risk associated with those whose magnesium intake was at least 280 mg/day compared to those whose magnesium intake was lower than 280 mg/day. There was also a significant increase in breast cancer risk when comparing participants with higher CRP levels; those with higher CRP and more chronic inflammation had a 1.43 times higher breast cancer risk compared to those with lower CRP levels and less chronic inflammation. (Note that the CRP units used by GrassrootsHealth are mg/L, so these values would be equivalent to >3 mg/L and <=3 mg/L.)

Mental Health, CRP, and Vitamin D

Multiple studies have found a direct correlation between levels of inflammation and mental health. In a previous blog, we reviewed a study assessing the effects of chronic inflammation on cognitive health, where higher levels of CRP were related to an increase in cognitive decline. A meta-analysis by Jamilian et al. reviewed the research available on inflammation, mental health, and vitamin D in patients diagnosed with psychiatric disorders. The review found a significant reduction in depression, improved quality of sleep, and a significant reduction in CRP following vitamin D supplementation.

Additional Relationships between CRP, Nutrients, and Disease Outcomes

Other diseases related to increased CRP levels which may be improved with certain nutrients include

Could Your Levels of Inflammation and CRP Improve with Vitamin D, Omega-3s, and Other Nutrients?

Reducing chronic inflammation can improve overall health and decrease the risk of many diseases. Add the hsCRP blood spot test to any GrassrootsHealth test kit to measure your level of inflammation, while also measuring your vitamin D, omega-3s, and essential minerals such as magnesium and zinc, by creating your custom home test kit today. Take steps to improve the status of each of these measurements to benefit your overall health. You can also track your own intakes, symptoms and results to see what works best for YOU.

When it comes to vitamin D especially, correcting a deficiency at any age and any time of life can decrease potential disease severity and improve outcomes. With almost 90% of the general population having vitamin D levels below the recommended 40-60 ng/ml (100-150 nmol/L), it is obvious that most people need more vitamin D. While most of us cannot achieve a vitamin D level of 40-60 ng/ml from sun alone, either due to our lifestyle, where we live, or other circumstances, we can certainly reach those levels with the right amount of supplementation.

Below is a guide for how much you might need, and who may need more. Your levels can be tested safely at home – order your home test kit today.

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By joining the GrassrootsHealth projects, you are not only contributing valuable information to our study, but you are also gaining knowledge about how you could improve your own health through measuring and tracking your nutrient status, and educating yourself on how to improve it. Do you know what your status of vitamin D, omega-3s, and other essential nutrients is? Could your levels be improved? Test now to find out!

We now have a NEW GIFTING SERVICE that allows you to quickly send ‘Gift Cards’ to friends, family and coworkers who you consider might need immediate access to testing, and to Claim the Joy of Your Health TODAY. Give the gift today!

What Does it Take YOU to Get Your D to 40 ng/ml (100 nmol/L)?

Did you know your health could be greatly affected by making sure you have a vitamin D level of at least 40 ng/ml (100 nmol/L)? Help us help you.

STEP 1 - Do you know what your vitamin D level is? If not, be sure to test today to find out.

STEP 2 – Determine your target level. Are you at your target level? Experts recommend a level of at least 40-60 ng/ml (100-150 nmol/L).

STEP 3 – Need to boost your level? Use the D*calculator to see how much vitamin D it may take to reach your target. Opt for the Loading Dose for a quicker boost.

STEP 4 – Optimize how your body absorbs and utilizes vitamin D with co-nutrients and these simple steps.

STEP 5 – Re-Test! This is an important step to make sure you have reached your target level, and to ensure you are not taking too much! Re-testing after 3-4 months is recommended.

STEP 6 – Adjust, Repeat…

Give your immune system the nutrients it needs to support a healthy you and protect yourself from unnecessary diseases, especially COVID-19.


The first Randomized Controlled Trial on vitamin D and COVID-19 has shown a 96% lower risk of ICU admission for those receiving vitamin D (as 25(OH)D to quickly boost vitamin D blood levels) along with the standard treatment, compared to those receiving standard treatment alone.

These results support many previous observational studies showing a relationship between vitamin D levels and intake and COVID-19 severity.

Review the Latest Nutrient Research for COVID-19

GrassrootsHealth Nutrient Research Institute has launched the new Immune Boost project with the use of our myData-myAnswers nutrient health system that nearly 15,000 people are already using for their health. Specific markers that influence immune health are suggested for testing as part of this project including:

  • Vitamin D
  • Omega-3 Index
  • Essential elements magnesium, selenium, and zinc
  • hsCRP

Our goal is to demonstrate how one can use the Nutrient Research Model established by Dr. Robert Heaney to show the effect of vitamin D serum levels of at least 40 ng/ml (100 nmol/L) on risk reduction for all ethnicities in the population. Status and intake of other nutrients will also be analyzed for any type of relationship to immune status and symptom severity. Join the project today!

Please let us know if you're interested in helping sponsor this project.

CLICK HERE for updates and new information about the project.

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 the Personal Health Nutrient Decision System called

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!