Does it require withholding vitamin D (Vit D) supplement before checking estradiol levels?

Yes, it is generally recommended to hold DHEA (dehydroepiandrosterone) supplements before checking estradiol levels. Ideally, you should discontinue DHEA for at least 1-2 weeks prior to blood testing to get an accurate baseline measurement of your natural estradiol levels. DHEA is a precursor hormone that can be converted to estrogens, including estradiol, in peripheral tissues. Taking DHEA supplements can artificially elevate your estradiol levels, potentially leading to inaccurate test results that don't reflect your body's natural hormone production. This could result in inappropriate treatment decisions if your healthcare provider is basing recommendations on these values. If you're unable to stop taking DHEA before testing, make sure to inform your healthcare provider that you're currently taking this supplement so they can interpret your results accordingly. Always consult with your healthcare provider before stopping any supplements, especially if they were prescribed for a specific condition.