Testing of vitamin D levels
GrassrootsHealth is sponsoring the use of blood spot test kits (laboratory analysis done by ZRT 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 is currently taking from 10-15 days from the time you record doing
the blood spot test (and mailing to GrassrootsHealth) until we post your
results (US addresses.) You will receive an email (to the email address
you provided as login to D*action) when we have the results.
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?
The same way you did the first one! Please login to D*action (www.grassrootshealth.net)
and complete the questionnaire. Your old data has been saved and except
for your primary information, the questionnaire is clear. Please
carefully review your answers. When you get to the end, if you have
already paid (a subscription), do not enter your credit card in PayPal
again – we already have your payment. Then, complete the blood spot
test, return it, and await your results!
Common Questions about Performing the Blood Spot 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 you fill the blood spot card.
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,
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: 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”.
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 42 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 42 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: How reliable is your vitamin D test?
GrassrootsHealth uses ZRT Laboratory (www.zrtlab.com). The key
consideration is that they have calibrated their results to the 'gold
standard', DiaSorin RIA (radioimmunoassay) so that their results
correlate directly with those. Click here to download a document from ZRT 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 MD's 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!
Copyright 2013 GrassrootsHealth. All rights reserved.