Skip Navigation


MVM Calculator Frequently Asked Questions (FAQ)
Calculator Development and Applications
1. How were the DSID prediction calculations developed?
2. For what dietary supplements can these predictions be used?
3. Why were multivitamin/minerals (MVMs) and these specific ingredients chosen for inclusion in the calculator?
4. How can these predicted values be used in nutrition studies?
5. How do I know what amount of each nutrient I need each day?
 
Data Terms and Explanation
6. Why does the children's MVM calculator have versions for two different age groups?
7. Why is "Vitamin A" provided rather than separate values for Beta Carotene and Retinol?
8. What is the "Predicted Mean Value"?
9. What are the "Standard Error for Predicted Mean" and the "Standard Error for Predicted Observation"?
10. How are the "Predicted Mean Value", "Standard Error for Predicted Mean" and "Standard Error for Predicted Observation" calculated?
11. What's the difference between a milligram (mg), microgram (mcg), and an International Unit (IU)?
12. How can I convert 'mg' or 'mcg' to 'IU' for vitamins A, D, and E?
 
Technical Questions for Using Calculator
13. Why do I receive error messages when I enter certain ingredient amounts?
1. How were the DSID prediction calculations developed?

The data used in the prediction calculations were derived from nationwide studies conducted to determine ingredient levels for representative multivitamin/mineral products (n = 3 or more vitamins, with or without minerals). Products were purchased from various market channels and analyzed for specific ingredients at qualified laboratories. Results from these studies were statistically evaluated using regression analysis. Details about each study can be accessed at the Research Summaries section of this website.
Return to Top
2. For what dietary supplements can these predictions be used?

DSID predicted values are based on analytical data for ingredients in adult multivitamin/mineral (MVM) and children's MVM products. MVMs in DSID studies are defined as dietary supplements containing three or more vitamins.
Return to Top
3. Why were multivitamin/minerals (MVMs) and these specific ingredients chosen for inclusion in the calculator?

A consortium of federal partners convened by the Office of Dietary Supplements established DSID priorities for products and ingredients of public health and research interest. MVM products were identified as a top priority because they are the most commonly reported dietary supplement in the NHANES. The vitamins and minerals for analysis were determined based on prevalence of consumption, public health interest, and the availability of reliable analytical methods for specific compounds.
Return to Top
4. How can these predicted values be used in nutrition studies?

DSID can support studies and surveys that estimate ingredient intake contributed by dietary supplements. DSID analytically-based estimates of mean and variablility can replace label information. These estimates can allow researchers to more accurately assess the nutritional status of the U.S population.
Return to Top
5. How do I know what amount of each nutrient I need each day?

The "Daily Value" (DV) amounts shown on labels are based on Reference Daily Intakes of essential vitamins and minerals and Daily Reference Values (which apply to fat, saturated fat, cholesterol, carbohydrate, protein, fiber, sodium, and potassium). For further details, refer to Daily Reference Intake (DRI) amounts recommended by the Institute of Medicine (IOM), accessible at http://fnic.nal.usda.gov/nal_display/index.php?info_center=4&tax_level=3&tax_subject=256&topic_id=1342&level3_id=5140 (accessed February 16, 2012)
Return to Top
6. Why does the children's MVM calculator have versions for two different age groups?

Many of the children's MVMs products in this study listed more than one age group or serving size on their labels. The laboratory data and the label information for each ingredient were examined and two datasets were created and analyzed independently. One contained children's products with label information for children that were 4 years and older (n=59 products), while the other dataset was for products with label information for children 1 to <4 years of age (n=50 products). Data associated with the age group, 4 years and older were determined to be the primary dataset for applying regression analysis results to products in population studies. Please see the Children's MVM Research Summary for more details.

The results for the percent differences from label at the most common labeled levels were similar for the 2 age groups. However, there are ingredients with significant differences between the predicted values for portions of the regression range. As a result, separate regression equations and a separate on-line calculator were created for each age group.
Return to Top
7. Why is "Vitamin A" provided rather than separate values for Beta Carotene and Retinol?

The major components of vitamin A, retinol and beta-carotene, were measured separately for these studies. The laboratory results were converted to International Units (IU) and combined as total vitamin A, for comparison to vitamin A (IU) on product labels.
Return to Top
8. What is the "Predicted Mean Value"?

The "Predicted Mean Value" is the estimated amount of that ingredient at a specific labeled level, as determined by regression analysis. Predicted means and other statistical parameters have been established within a defined regression range for each ingredient. For example, the defined regression range for iodine is labeled levels of 15 to 150 mg for adults and 12.8 to 150 mg for children ages 4 and older. For labeled levels above and below those amounts, predicted amounts are not available.
Return to Top
9. What are the "Standard Error for Predicted Mean" and the "Standard Error for Predicted Observation"?

The "Standard Error for Predicted Mean" is the standard deviation of a sampling distribution of means, calculated in this study by dividing the standard deviation by the number of analytical values. This is the error associated with the predicted mean for a large population of supplements labeled at the same level. The "standard error for predicted observation" estimates the error associated with the predicted mean for a single new observation, which in this case is an individual MVM supplement product.
Return to Top
10. How are the "Predicted Mean Value", "Standard Error for Predicted Mean" and "Standard Error for Predicted Observation" calculated?

These values are calculated from statistical data provided in Table 1 or Table A1of the DSID-2 release. An Example Calculations document provides definitions and instructions for applying the data in Table 1 to labeled levels of MVM supplement products. A spreadsheet version of the Example Calculations is available in the second tab of the Table 1 and Table A1 Excel spreadsheet.
Return to Top
11. What's the difference between a milligram (mg), microgram (mcg), and an International Unit (IU)?

In the metric system, 1000 milligrams (mg) is a unit of mass equal to 1 gram and 1000 micrograms (mcg) is equal to 1 milligram (mg).

An IU (International Unit) is a unit of measurement for vitamins and other specific biologically active substances. The precise measure of one IU differs from substance to substance and is established by international agreement for each substance. For example, vitamin E exists in a number of different forms having different biological activities. Rather than specifying the precise type and mass of vitamin E in a preparation, the Supplement Facts label summarizes the biological activity of the forms present as the number of International Units of vitamin E.

The equivalents of 1 IU for selected vitamins are:
  • Vitamin A: 1 IU is the biological equivalent of 0.3 mcg retinol, or of 0.6 mcg beta-carotene
  • Vitamin D: 1 IU is the biological equivalent of 0.025 mcg cholecalciferol or ergocalciferol
  • Vitamin E: 1 IU is the biological equivalent of 0.67 mg d-alpha-tocopherol, or 0.9 mg of dl-alpha-tocopherol
Return to Top
12. How can I convert 'mg' or 'mcg' to 'IU' for Vitamins A, D and E?

To convert Vitamin A as retinol:
      From IU to mcg:  IU/3.33 = mcg
      For example: 5000 IU/3.33 = 1500 mcg
      From mcg to IU: mcg * 3.33 = IU

To convert Vitamin A as beta-carotene:
      From IU to mcg:  IU/1.66 = mcg
      From mcg to IU: mcg * 1.66 = IU

To convert Vitamin D:
      From IU to mcg: IU/40 = mcg
      For example: 400 IU/40 = 10 mcg
      From mcg to IU: mcg * 40 =IU

To convert Vitamin E if the product label has dl-Alpha-tocopherol as the ingredient:
      From IU to mg: IU * 0.9 = mg
      For example:  30 IU * 0.9 = 27 mg
      From mg to IU: mg * 1.1 = IU

To convert Vitamin E if the product label has d-Alpha-tocopherol as the ingredient:
      From IU to mg: IU * 0.67 = mg.
      For example: 30 IU * 0.67 = 20.1 mg
      From mg to IU: mg * 1.5 = IU
Return to Top
13. Why do I receive error messages when I enter certain ingredient amounts?

Probably one of two events has occurred. Either you have entered a decimal value that is not acceptable or a value that is outside the established regression range for that ingredient. All ingredients allow a label value to be entered with up to 3 places after the decimal point. Each ingredient has a numeric range for which the predictions are valid, which is shown on the screen for each nutrient. Entering a value outside this range will result in an error message.
Return to Top

 

PDF documents are best viewed with the free Adobe® Reader