Published on September 3, 2019

On May 27, 2016, the U.S. Food and Drug Administration (FDA) published new rules for Nutrition Facts labels that affect how labels read on vitamin D supplements and food products containing vitamin D. Two of these new rules affect vitamin D labeling:

  1. Vitamin D is now required to be listed in units of micrograms (mcg) instead of International Units (IU). While the product manufacturer does have the option to also list IU in parentheses, they are not required to. (The units of measure on the label will also change for other nutrients, including vitamin A, vitamin E, and folate)
  2. The label must show the new or updated % Daily Value (DV); in the case of vitamin D, some supplements still use the outdated recommended DV of 400 IU vitamin D per day, which has since been updated by the Institute of Medicine to 600 IU per day.

Manufacturers are required to begin using the new labels by January 1, 2020, however, some have already begun to implement the changes. You may also notice other changes that are not related to vitamin D, such as different font sizes, new nutrients included, and the consistent use of metric units.

How to convert mcg to IU

It may take a bit of time to immediately recognize if a vitamin D supplement has the amount of vitamin D in it that you are looking for. In the meantime, remember this conversion:

1 mcg = 40 IU Vitamin D

Some of the more common doses would show as follows:

10 mcg = 400 IU
20 mcg = 800 IU
25 mcg = 1000 IU
100 mcg = 4000 IU
125 mcg = 5000 IU
250 mcg = 10,000 IU

Use the GrassrootsHealth.net mcg to IU Calculator

To help with conversion, GrassrootsHealth has created an online calculator for you to use. You can always find this calculator and our other calculators, such as our ng/ml to nmol/L calculator and our intake calculators, under the “Calculators” tab on the main navigation menu of our website. Click here to view the calculator now.

Are you getting enough vitamin D?

Testing your vitamin D level regularly and taking daily steps to keep it at a target level of 40-60 ng/ml (100-150 nmol/L) is important for all stages of health. Find out your levels today! Log on to the shop (click the link below) to get your tests and see for yourself if your level can be improved.

Make sure you track your results before and after, about every 6 months!

Click Here to Access the Shop Page

How can I track my nutrient intake and levels over time?

To help you track your supplement use and nutrient levels, GrassrootsHealth has created an online tracking system called myData-myAnswers. For each specific supplement, you can track what days you take it, how much, and many other details. This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels. Check it out today!

How Can You Use this Information for YOUR Health?

Having and maintaining healthy vitamin D and other nutrient levels can help improve your health now and for your future. Measuring is the only way to make sure you are getting enough!

STEP 1 Order your at-home blood spot test kit to measure vitamin D and other nutrients of concern to you, such as omega-3s, magnesium, essential and toxic elements (zinc, copper, selenium, lead, cadmium, mercury); include hsCRP as a marker of inflammation or HbA1c for blood sugar health

STEP 2 Answer the online questionnaire as part of the GrassrootsHealth study

STEP 3 Using our educational materials and tools (such as our dose calculators), assess your results to determine if you are in your desired target range or if actions should be taken to get there

STEP 4 After 3-6 months of implementing your changes, re-test to see if you have achieved your target level(s)

Enroll in D*action and Build Your Custom Test Kit!