Postpartum depression has been associated with delays in infant motor development, which may be due, in part, to the increased cortisol levels in depressive mothers. Low vitamin D status has also been linked to motor development delay.

Sunlight has been shown to improve symptoms of depression, decrease cortisol levels, and improve vitamin D status.

Last month (July 2019), results from a clinical trial assessing whether sunlight and vitamin D supplements could improve delayed early motor development in infants with mothers suffering from postpartum depression were published. In this trial, 229 infants were assigned to one of four groups: 400 IU/day of vitamin D, 1000 IU/day of vitamin D, 400 IU/day of vitamin D plus sunlight, or neither vitamin D nor sunlight. Those in the vitamin D plus sunlight group were further divided into groups based on sunlight style (both mother and infant exposed or only infant exposed) and duration (2-7 hours/week or 7-14 hours/week) while those in the vitamin D groups were further divided into groups for sunlight exposure for the mother only or neither mother nor infant exposed (less than 2 hours/week). As a comparison group for motor development, 120 infants from non-depressive mothers were also included.

What were the findings of the study?

Within 2 days postpartum, infants from depressed mothers had lower motor development scores and increased cortisol levels compared to the infants from non-depressive mothers (P<0.05). As shown on the charts below, infants in the vitamin D (400 IU/day) plus sunlight group had better motor development scores and lower cortisol levels over the next two months compared to infants only taking vitamin D supplements (400 or 1000 IU/day) or the control group (P<0.05).

Click to Enlarge & Print

Infants in the highest sun exposure group (7-14 hours/week) achieved the best scores and had the lowest cortisol levels (P<0.05). Further, mothers who received sunlight exposure had improved depression scores and lower cortisol levels compared to mothers who did not receive sunlight exposure (P<0.05).

These findings indicate that sunlight and vitamin D supplements combined can improve motor development, lower cortisol levels, and improve depressive symptoms. For more information about the health benefits of the sun, check out these previous blog posts.

Are you deficient in vitamin D?

Testing your vitamin D level regularly and taking daily steps to keep it 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 sun exposure and vitamin D levels?

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