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Which vitamins should I take?

Finding out which nutrients you are deficient in is the first step to determining which vitamins or supplements you should be taking. Check out our nutrient testing page to see the extensive number of tests that our lab offers. Bio-Center Lab at Riordan Clinic is an open laboratory, and as such, individuals can order laboratory testing without an order from a physician. For more information about our lab you can go  to You may also call 1-800-447-7276 to speak with a lab representative.

Why would I choose your vitamins?

With impressive credentials and decades of experience, the physicians at the Riordan Clinic provide the very best in care and expertise. Each of our nutrients is chosen by our expert medical staff based on quality, purity, consistency and effective dosing.

How do I find out what products I ordered last time?

There are a couple of ways to find out what products you have ordered previously. If you have created an account through our online store you can log in and select "Orders" to view all previous orders placed through that account. If you have not ordered online then you may contact us at Riordan Clinic and we will be happy to look up your account information.

How much of my vitamins should I take?

When taking any kind of vitamin or supplement you should always consult with your health care professional. Having the proper testing done is vital in finding out where your deficiencies may lie.

How do you leave a product review?

We would love to hear how you feel about the different products we offer. If you would like to write a review first you must log into or create an online account. Then select the product you would like to review. Below the product name and price you will see 5 stars, next to the stars click on the link for "Write a Review"  You may then rate the item and tell us what you think. Your reviews and opinions are important to us and we love hearing from you.

Do you ship internationally?

We are happy to ship internationally pending customs regulations. All international orders must be placed over the phone (1-800-447-7276 ext. 1464) or by email ( They cannot be placed through our online store at this time. Shipping charges for International orders are estimations and subject to change based on product weight and packaging. We reserve the right to update your order to reflect the actual shipping charges to your country.

All duties, taxes & other national fees are the responsibility of the customer. Please, check with your local agencies to determine whether any local taxes or duties are in effect for your shipping address before ordering. We are not able to determine and apply these charges at time of purchase.

What vitamins can I take with my prescriptions?

Make sure you discuss any medications you are taking with your health care professional before starting on any supplements..

How soon will my order be shipped?

Orders will be shipped within 1-2 business days of receipt. Orders placed over the weekend, holidays or during a sale may take an extra day for processing and/or delivery.

How do I talk with a Riordan Clinic representative?

To contact a Riordan Clinic Store representative you may call 1-800-447-7276

What happens if I haven’t received my product?

If you have not received your product within 5-7 days of placing your order please contact our shipping department. They can then pull up any tracking information and reach out to the shipping company if necessary. 

Why can’t I find my product online?

Some manufacturer policies prohibit the selling of their products online. These manufacturers include: Klaire Labs, Standard Process/Medi Herb, Seroyal, Karuna Corporation and Xymogen / NuMedica. To purchase products from these manufacturers, please call 1-800-447-7276 to place your order.

What is your return policy?

We believe everyone deserves the best quality product. We ask that you check your items carefully, as once they have been purchased they cannot be returned or exchanged.


The products and the claims made about specific products on or through this site have not been evaluated by Riordan Clinic or the United States Food and Drug Administration and are not approved to diagnose, treat, cure or prevent disease. The information provided on this site is for informational purposes only and is not intended as a substitute for advice from your physician or other health care professional or any information contained on or in any product label or packaging. You should not use the information on this site for diagnosis or treatment of any health problem or for prescription of any medication or other treatment. You should consult with a healthcare professional before starting any diet, exercise or supplementation program, before taking any medication, or if you have or suspect you might have a health problem. Not responsible for typographical errors or misprints. Product availability, pricing, and promotions are subject to change without notice.