Most of the vitamin D we have in our bodies is in the form of vitamin D3, which is synthesized in the skin upon exposure to sunlight and other forms of UVB radiation. Additional sources of vitamin D3 are from supplements, with a small amount coming from foods, mainly animal food sources such as meat, eggs and dairy. Other foods with vitamin D are those that are fortified and some plant foods, although these mostly contain vitamin D2.

Which foods have the greatest impact on vitamin D levels?

An analysis by GrassrootsHealth looked at which foods had the greatest effect on serum levels of vitamin D (as 25(OH)D3), and found that the foods that had the most impact were whole milk cottage cheese, eggs, meat, and total protein.

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Vitamin D in plants

Most of the vitamin D found in plants is in the form of vitamin D2. Fungi and yeasts produce vitamin D2 in response to UVB exposure, with wild mushrooms having the highest content. An interesting observation is that plants with higher levels of sun exposure and plants at a higher level of maturity contain more vitamin D2.

What about vitamin D3 in plants?

For many years it was believed that only vitamin D2 was present in plants, however, scientists have recently discovered vitamin D3 in some plant species. Vitamin D3 has been found in microalgae, both as vitamin D3 and provitamin D3 (the form that is converted to vitamin D3 upon exposure to UVB).

Fruits and vegetables, especially those in the Solanaceae family (which includes potatoes, tomatoes, and peppers), have the potential for containing some vitamin D3, although current research can only support that there is measurable vitamin D3 in the leaves of these plants.

Other foods with vitamin D

Some foods known to contain vitamin D include:

  1. Salmon (significantly more found in wild salmon vs farmed salmon)
  2. Herring and Sardines (including pickled)
  3. Cod Liver Oil
  4. Canned Tuna (Light tuna may be a better choice since it contains less methylmercury than solid white)
  5. Oysters (also high in vitamin B12, copper and zinc)
  6. Shrimp (one serving contains approximately 152 IU of vitamin D)
  7. Egg Yolks (higher amounts found in eggs from pasture-raised chickens and those fed vitamin D enriched feed)
  8. Mushrooms (wild or those treated with UV light)
  9. Foods fortified with vitamin D

Are you using foods as a source of vitamin D and omega-3?

Is food, whether those containing vitamin D3 or vitamin D2, helping to improve your vitamin D level? How about foods with omega-3s? Testing your vitamin D and Omega-3 Index levels and taking daily steps to keep your Omega-3 Index at a target of at least 8%, and your vitamin D at a target level of 40-60 ng/ml (100-150 nmol/L), is important for all stages of health. Find out your levels today! Log on to the shop (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 Shop Page

How can I track my food intake and my vitamin D and omega-3 levels?

To help you track your food intake along with vitamin D levels, GrassrootsHealth has created an online tracking system called myData-myAnswers. You can also track your sun exposure and supplement use to see how vitamin D from food, sun and supplements impact your vitamin D levels and your health. Check it out today!

Important Message

NEWS ALERT: States, Governments Acknowledge the Need for Vitamin D to Build the Immune System; Vitamin D*action has achieved a major milestone of ‘Moving Research into PRACTICE’!

EVERYONE needs to know about the benefits of vitamin D... We need your help to do this. Donating $25.00 today will positively affect millions of lives!

We will take this opportunity to use our extensive network to get pertinent information on vitamin D to the new US COVID Panel as well as local and state government representatives around the world.

Donate $25 today to help support this outreach effort (and, let us know if your employer could match the donations made by individuals from now until January 1, 2021!). You can also "text-to-give" by simply texting Daction to 44321.

Donations made through GiveLively are received in full by GrassrootsHealth.

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!