Testing of vitamin D levels
GrassrootsHealth is sponsoring the use of blood spot test kits (laboratory analysis done by Purity Labs) for
a $60.00 fee to each individual. The tests are to be done twice a year by each individual along with the
submission of some basic health data. The kits are not available as a ‘stand alone’ without health data.
A 5 year study will be done with the data
accumulated from the individuals tested to evaluate the results of the program in disease prevention and
to help create a long term plan for public health.
Q: How long does it take to receive my blood spot test?
After you complete your questionnaire and pay for your test, your order
is fulfilled within 2 business days. We ship first class mail from San
Q: How do I find my participant ID?
You received an email from GrassrootsHealth with a subject “Thanks for
joining D*action”, the participant ID is in that email. Alternatively,
you may login to D*action ( www.grassrootshealth.net);
scroll down the page until you see a box; click on “Start or review the
D*action Participant Questionnaire now”. The next page that appears
lists your participant ID right under the header.
Q: I lost my password. How do I get into my account?
Go to www.grassrootshealth.net
and click on “Need New or Forgot Password?” in the left column. The
system will then email you a new password. Use this password to login.
You may then change your password by clicking on “account settings” in
the left column.
Q: I don’t remember the email I used to login.
with your name, address, and phone number. We will let you know which email you used as your login.
Q: I want to change my email for D*action.
Since your email is your login, this must be changed by GrassrootsHealth. Please email
with your name, old email (login) and new email. We will notify you when it is changed.
Q: I never received a confirmation email; did I pay for a test?
We can let you know your status and when you will receive the blood
spot test. Typically you will receive the blood spot test within 5-7
business days of completing the questionnaire and paying for the test.
Q: Can I participate if I live in _______?
Absolutely! The only place we can’t ship to is New York.
Q: Why can't NY residents take part in the study?
Due to New York State's health department regulations we are not
allowed to ask the participant to send dried blood spot cards outside of
the state. If you have a residence outside the state of New York,
please let us know (and, change your address in the questionnaire). We
can then ship you the kit and process your results.
Q: How long does it take to receive my results?
It takes 7-10 days from the time we receive your completed blood spot test with questionnaire until we post your
results; incomplete questionnaires will cause an additional delay. You will receive an email (to the email address
you provided as login to D*action) when we have the results, which will be posted to your www.grassrootshealth.net account.
Q: Is there an additional cost to mail a kit overseas?
No. You just have to pay postage on the return envelope.
Q: I signed up for the whole study and now it is time for me to take my second test, how do I do that? If you signed up for the whole study through the 5 year subscription, your blood spot kit will automatically be sent to you each 6 months with an email reminder and a deduction from your credit card. When you receive the kit, you need to login to D*action and complete the questionnaire. When you get to the end and you have already paid, do not enter your credit card in PayPal again - we already have your payment. Simply hit the "Save and Exit" button, then complete the blood spot test, return it, and await your results!
Q: What about the cost of the test? $65 seems high for a blood test. If you are a non-profit, can I get a test for free? GrassrootsHealth is a non-profit organization. We do not currently receive funding from any government agency or granting organization. Instead, we are funded by donations and personal sponsors. Your $65 goes to lab processing fees and materials and all the promotional work that we do (seminars, videos, research). We are currently seeking additional funding through grants but for now, we are entirely dependent on each of you to move research into practice. Please know that we value your support and understand that without your participation, there is no D*action.
Common Questions about Performing the Blood Spot Test
Q: How do I do this blood spot test?
To make the process as easy as possible, we created a 5-minute video to guide you through the process from start to finish. The video can viewed here and provides you with recommendations to successfully complete the test.
Q: How do I get more blood to flow?
Make sure you wash your hands under very warm water. Try pricking the
side of your pinky finger and wipe the first spot of blood off with
gauze. Then, milk your finger as your blood drop grows, and drop it onto blood spot card. We highly suggest watching our video for steps and tips on how to complete the blood spot test, found here: http://www.youtube.com/watch?v=By4wQYV-UzU.
Q: I am worried my blood spots are not big enough. Can I get another card?
Yes, but first measure your blood spots; if you have one spot that is 6
mm (1/4”) in diameter, then the card is valid. Or you can have 2 spots
that are (1/8”) 4.5 mm in diameter. If you didn’t get that much blood, you can apply additional drops anywhere on the filter paper, as long as the blood drops do not overlap with each other. Otherwise, email
and we can mail you another blood spot card and lancets
Q: Can blood be taken from other parts of the body?
Yes, your earlobe and toes are two other good alternative areas.
Q: Will my blood spot test expire?
The kit itself does not expire, however for D*action data to be accurate we require the questionnaire to be filled out within 2 months of the blood spot collection date. If you delay too much in filling out the questionnaire after your blood spot date, then we may ask you to fill out another blood spot card.
Q: What happens to my blood spot sample once my test has been completed?
After the lab report results, they store the blood spot cards in freezers for a period of 90 days. At the end of the 90 days, they are destroyed following the laboratory's procedure for biological waste.
Q: I am a doctor and promote vitamin D and D*action frequently, can I link to your web site?
Absolutely! You may advertise our web site as much as you want.
Unfortunately, at this time we are not publicizing doctors or clinics
that promote vitamin D. We only list the scientists that are involved in
Q: I would like to handout more vitamin D materials at work/home/play. Can you provide any?
If you notice, many of our pages also have a pdf form. Just check the
bottom of the page and click on “Printable Download (PDF)”. On the home
page are two very good documents for this –
“Scientist's Call to D*action” and “Disease Incidence Prevention Chart”. Additional downloads can be found on our Documentation page. We also distribute a tri-fold “Does Vitamin D Prevent Cancer?” and some
cards, “Scientists’ Call to D*action”. We would appreciate a donation
for these; email
to let us know how many you need.
Vitamin D Health Questions
Q: Why does
GrassrootsHealth recommend having 40-60 ng/ml of vitamin D (25 OH D) as
opposed to 50 ng/ml or 60 ng/ml being the lower limit on some of the
other vitamin D web sites?
GrassrootsHealth has gathered a group of 43 researchers/practitioners
who AGREE that at least 40-60 ng/ml is necessary. The key to our public
health effort is to have a 'consistent' message, and all 43 members
agree that 40 ng/ml is the minimum. There are, as you note, people who
think it should be higher. Getting everyone to at least 40 ng/ml is
still a major achievement, however! This would solve many of today’s
world-wide health problems.
Q: How quickly does supplementation take effect?
Generally, with a constant dose, it takes about 3 months of dosing in
order to reach a plateau. However, there are some regimens which use
very high doses for a few days or weeks to push up the level more
Q: My D level seems to have changed dramatically from the last test, is that valid?
Before questioning the test, think about what has changed in your life. Have you changed any of your supplements recently (probiotics, vitamin K, fish oil)? Over the last few months was there a period, even if only a few days, when you may have taken more than your usual dose to help fight off a cold or flu or just recover from an injury? Have you changed anything in your diet recently? Eating more or less fish, eggs, raw dairy products or fermented foods (sauerkraut, kimchi, yogurt, cottage cheese)? Any of these could be a factor in your vitamin D level.
Q: How reliable is your vitamin D test? Any lab used by GrassrootsHealth has Clinical Laboratory Improvement Amendments (CLIA) certification. The Centers for Medicare & Medicaid Services (CMS) regulates all laboratory testing (except research) performed on humans in the U.S. through the Clinical Laboratory Improvement Amendments (CLIA). In total, CLIA covers approximately 225,000 laboratory entities. The Division of Laboratory Services, within the Survey and Certification Group, under the Office of Clinical Standards and Quality (OCSQ) has the responsibility for implementing the CLIA Program. The objective of the CLIA program is to ensure quality laboratory testing. Although all clinical laboratories must be properly certified to receive Medicare or Medicaid payments, CLIA has "no direct Medicare or Medicaid program responsibilities."
The GrassrootsHealth program does not participate in any Medicare or Medicaid payments.
Scientists at the National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of Health's Office of Dietary Supplements, have developed a new reference sample for vitamin D in blood serum to help laboratories validate the accuracy of their test methods. NIST Standard Reference Material (SRM) 972, “Vitamin D in Human Serum.” All GrassrootsHealth laboratories use the NIST reference sample to calibrate their results on a regular basis.
Currently GrassrootsHealth uses Purity Laboratory (www.puritylabsinc.com). The key consideration is that they are a participant in DEQAS, the Vitamin D External Quality Assessment Scheme, and have received their Certificate of Proficiency certifying that they have met the performance target of the assessment panel. Click here to download a document from Purity which gives more information.
Q: What is the D2 level that is reported with my blood spot test? What does it mean?
D2 is frequently very low or '0'. The only sources of D2 are from some
supplements and maybe a small amount in foods. D3 is what your body
makes from the sun and that's the version of the supplement that our
Q: Can you recommend a doctor that understands D health?
At this point in time, we do not have a list of clinics or MDs that we
recommend. When you visit your doctor, take a copy of the Disease
Incidence Prevention Chart (download from www.grassrootshealth.net) and the Call to D*action and discuss it with him/her. That's a good way to start!
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