Whether you’re looking for a simple vitamin D test or want to contribute to advancing vitamin D research, GrassrootsHealth offers two trusted ways to measure your vitamin D levels.
Both options use the same convenient at-home blood spot test and provide you with the information you need to optimize your vitamin D status. The difference is how you’d like to use your results.
Help advance research while learning about your own health.
Perfect for individuals who want to:
Fast, simple vitamin D testing with no study participation.
Ideal for:
| Feature |
D*action Study
Research + Testing
|
CheckYourD
Testing Only
|
|---|---|---|
| At-home finger-prick blood spot test | ✓ | ✓ |
| Vitamin D results sent directly to you | ✓ | ✓ |
| Personalized guidance to optimize vitamin D | ✓ | ✓ |
| Participate in scientific research | ✓ | — |
| Online health questionnaire | Required | Not required |
| Study enrollment | Required | Not required |
| Supports vitamin D research and education | ✓ | — |
| Additional nutrient testing available | ✓ | — |
| Vitamin D only testing | Optional | ✓ |
| Wholesale pricing for practitioners | — | ✓ |
| Best for organizations and wellness programs | — | ✓ |
Testing is only the first step toward optimizing your health.
Whether you test through the D*action Study or CheckYourD, GrassrootsHealth provides tools and educational resources to help you understand your results and take action.
You’ll have access to resources such as:
Start with an accurate vitamin D blood spot test.
Use the Vitamin D Calculator to estimate your personalized daily dose.
Apply your personalized vitamin D, nutrition, and lifestyle plan.
Measure again in 3–6 months to confirm your progress.
Fine-tune your intake and continue optimizing your health over time.
Both options use the same trusted at-home blood spot testing method and provide reliable vitamin D results.
Only if you choose the GrassrootsHealth D*action Study. CheckYourD does not require study participation.
Yes. CheckYourD offers wholesale purchasing options for qualified healthcare professionals, organizations, employers, retailers, and wellness programs.
Yes. The D*action Study offers additional testing options for nutrients and health markers such as omega-3s, magnesium, zinc, inflammation markers, and more.
No matter which option you choose, measuring your vitamin D level is the first step toward better health.
