Table of Contents

Locator Record

Title: Vitamins A, E and Carotenoids (L06VIT_B )
Contact Number: 1-866-441-NCHS
Years of Content: 2001 - 2002
First Published: October, 2007
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject:fat-soluble micronutrients
Record Source: NHANES 2001 - 2002
Survey Methodology: NHANES 2001 - 2002 is a stratified multistage probability sample of the civilian non-institutionalized population of the U.S.
Medium: NHANES Web site; SAS transport files

Component Description

The objectives of this component are:

  1. to provide data for monitoring secular trends in measures of nutritional status in the U.S. population;
  2. to evaluate the effect of people's habits and behaviors such as physical activity and the use of alcohol, tobacco, and dietary supplements on people's nutritional status; and
  3. to evaluate the effect of changes in nutrition and public health policies including welfare reform legislation, food fortification policy, and child nutrition programs on the nutritional status of the U.S. population.

These data will be used to estimate deficiencies and toxicities of specific nutrients in the population and subgroups, to provide population reference data, and to estimate the contribution of diet, supplements, and other factors to serum levels of nutrients. Data will be used for research to further define nutrient requirements as well as optimal levels for disease prevention and health promotion.

Eligible Sample

Participants aged 3 years and older who do not meet any of the exclusion criteria are eligible.

Description of Laboratory Methodology

Serum concentrations of vitamins A (retinol) and E (α and γ-tocopherol), two retinyl esters, and six carotenoids (α-carotene, trans-β-carotene, cis β-carotene, β-cryptoxanthin, combined lutein/zeaxanthin, and trans-lycopene) are measured using high performance liquid chromatography with photodiode array detection. A small volume (100 μL) of serum is mixed with an ethanol solution containing two internal standards- retinyl butyrate and nonapreno-β-carotene (C45). The micronutrients are extracted from the aqueous phase into hexane and dried under vacuum. The extract is redissolved in ethanol and acetonitrile and is filtered to remove any insoluble material. An aliquot of the filtrate is injected onto a C18 reversed phase column and isocratically eluted with a mobile phase consisting of equal parts of ethanol and acetonitrile. Absorbance of these substances in solution is linearly proportional to concentration, thus spectrophotometric methods are used for quantitative analysis. Three wavelengths, approximately corresponding to absorption maxima, namely, 300, 325, and 450 nm, are simultaneously monitored and chromatograms are recorded. Quantitation is accomplished by comparing the peak height of the analyte in the unknown with the peak height of a known amount of the same analyte in a calibrator solution. Calculations are corrected based on the peak height of the internal standard in the unknown compared with the peak height of the internal standard in the calibrator solution. Retinol and the retinyl esters are compared with retinyl butyrate at 325 nm, α-and γ-tocopherol are compared with retinyl butyrate at 300 nm, and the carotenoids are compared with C45 at 450 nm.

Data Processing and Editing

Serum specimens were processed, stored, and shipped to the Division of Laboratory Sciences, National Center for Environmental Health, and Centers for Disease Control and Prevention for analysis. Detailed specimen collection and processing instructions are discussed in the NHANES LPM. Vials were stored under appropriate frozen (–20°C) conditions until they were shipped to National Center for Environmental Health for testing.

Eleven derived variables were created in this data file. The formula for their derivatization is as follows:

The vitamin A (retinol) results in ug/dL were converted into umol/L by multiplying by 0.03491.

The retinyl palmitate results in ug/dL were converted into umol/L by multiplying by 0.03491.

The retinyl stearate results in ug/dL were converted into umol/L by multiplying by 0.03491.

The vitamin E (α-tocopherol) results in ug/dL were converted into umol/L by multiplying by 0.02322.

The γ-tocopherol results in ug/dL were converted into umol/L by multiplying by 0.02402.

The α-carotene results in ug/dL were converted into umol/L by multiplying by 0.01863.

The trans-β-carotene results in ug/dL were converted into umol/L by multiplying by 0.01863.

The cis-β-carotene results in ug/dL were converted into umol/L by multiplying by 0.01863.

The β-cryptoxanthin results in ug/dL were converted into umol/L by multiplying by 0.01810.

The combined lutein/zeaxanthin results in ug/dL were converted into umol/L by multiplying by 0.01758.

The trans-lycopene results in ug/dL were converted into umol/L by multiplying by 0.01863.

Laboratory Quality Assurance and Monitoring

The NHANES quality assurance and quality control (QA/QC) protocols meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed QA/QC instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM). Read the LABDOC file for detailed QA/QC protocols.

There weren’t any changes to the laboratory, method, or site from 1999-2000.

A detailed description of the quality assurance and quality control procedures can be found on the NHANES website.

Analytic Notes

The analysis of NHANES 2001–2002 laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES 2001–2002 Household Questionnaire Data Files contain demographic data, health indicators, and other related information collected during household interviews. The Household Questionnaire Data Files also contain all survey design variables and sample weights required to analyze these data. The Phlebotomy Examination file includes auxiliary information on duration of fasting, the time of day of the venipuncture, and the conditions precluding venipuncture. The Household Questionnaire and Phlebotomy Exam files may be linked to the laboratory data file using the unique survey participant identifier SEQN.

Regression Analysis for 2001-2002 and 2003-2004 for Vitamins A, E, and Carotenoids:

In 2001-2002, Vitamins A, E and Carotenoids were analyzed using a HPLC method performed at CDC/NCEH. In 2003-2004, Vitamins A, E and Carotenoids were analyzed using a comparable HPLC method at Craft Technologies, Inc. (CTI) [See Lab 45 in NHANES 2003-2004 for method details]. Crossover studies between CDC/NCEH and CTI were done in early 2003 and late 2004 and differences existed between the methods for some analytes. The following Deming regression analyses were performed to compare data from 2001-2002 to 2003-2004:

Early 2003 Deming Regression Analysis for A/E/Carotenoids Y(CDC)=X(CTI) in μg/dL
Test n Y(CDC)=X(CTI)  r2 
Alpha-Carotene 100 y = 0.9734x + 0.1847 0.9944
Trans-Beta-Carotene 100 y = 1.0764x - 0.0248 0.9971
 Cis-Beta-Carotene 100 y = 0.8017x - 0.0372 0.9685
 Beta-Cryptoxanthin 100 y = 1.1359x - 0.2116 0.9945
 Gamma-Tocopherol 100 y = 1.0346x - 8.5749 0.9818
 Lutein/Zeaxanthin 99 y = 0.9321x + 0.1231 0.9455
 Trans-Lycopene 100 y = 1.0719x - 0.1817 0.9947
Retinyl Palmitate 100 y = 1.0245x + 0.5039 0.1988
Retinyl Stearate 97 y = 0.803x - 0.0048 0.9807
Vitamin A 100 y = 0.9406x - 0.1199 0.9887
Vitamin E 100 y = 0.9541x - 22.231 0.9941

Late 2004 Deming Regression Analysis for A/E/Carotenoids Y(CDC)=X(CTI) in μg/dL
Test n Y(CDC)=X(CTI)  r2 
Alpha-Carotene 99 y = 0.9989x + 0.2204 0.9768
Trans-Beta-Carotene 98 y = 1.0275x + 1.2976 0.9960
 Cis-Beta-Carotene 99 y = 0.7154x + 0.1344 0.9826
 Beta-Cryptoxanthin 98 y = 1.0824x - 0.056 0.9696
 Gamma-Tocopherol 98 y = 1.0306x - 5.523 0.9922
 Lutein/Zeaxanthin 99 y = 1.1082x - 1.602 0.9141
 Trans-Lycopene 98 y = 1.0971x + 0.0645 0.9737
Retinyl Palmitate 98 y = 0.7989x + 1.2106 0.8845
Retinyl Stearate 98 y = 0.7681x + 0.1483 0.9621
Vitamin A 99 y = 0.9806x + 0.2901 0.9934
Vitamin E 98 y = 0.93x + 22.614 0.9905

Combined Deming Regression Analysis for A/E/Carotenoids Y(CDC)=X(CTI) in μg/dL
Test n Y(CDC)=X(CTI)  r2 
Alpha-Carotene 199 y = 0.9837x + 0.2137 0.9877
Trans-Beta-Carotene 198 y = 1.0339x + 0.8812 0.9960
 Cis-Beta-Carotene 199 y = 0.7232x + 0.0879 0.9815
 Beta-Cryptoxanthin 198 y = 1.0958x - 0.0542 0.9793
 Gamma-Tocopherol 198 y = 1.029x - 6.287 0.9893
Lutein/Zeaxanthin 198 y = 1.0641x - 1.2402 0.9225
 Trans-Lycopene 198 y = 1.0852x - 0.0681 0.9849
Retinyl Palmitate 198 y = 0.8227x + 0.99 0.7603
Retinyl Stearate 195 y = 0.7881x + 0.0711 0.9675
Vitamin A 199 y = 0.9805x - 1.0069 0.9871
Vitamin E 198 y = 0.9397x + 1.649 0.9914

The combined regression was performed using crossover data from early 2003 and late 2004. The data user may wish to apply regression formulas to compare results from 2001-2002 and 2003-2004.

References

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 3 YEARS - 150 YEARS

LBXALC - a-carotene(ug/dL)

Variable Name:
LBXALC
SAS Label:
a-carotene(ug/dL)
English Text:
a-carotene(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.7 to 190.6 Range of Values 7614 7614
0.49 Fill Value of Limit of Detection 745 8359
. Missing 903 9262

LBDALCSI - a-carotene(umol/L)

Variable Name:
LBDALCSI
SAS Label:
a-carotene(umol/L)
English Text:
a-carotene(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.013 to 3.551 Range of Values 7614 7614
0.009 Fill Value of Limit of Detection 745 8359
. Missing 903 9262

LBXBEC - trans-b-carotene(ug/dL)

Variable Name:
LBXBEC
SAS Label:
trans-b-carotene(ug/dL)
English Text:
trans-b-carotene(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.8 to 242.3 Range of Values 8351 8351
0.57 Fill Value of Limit of Detection 7 8358
. Missing 904 9262

LBDBECSI - trans-b-carotene(umol/L)

Variable Name:
LBDBECSI
SAS Label:
trans-b-carotene(umol/L)
English Text:
trans-b-carotene(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.015 to 4.514 Range of Values 8351 8351
0.011 Fill Value of Limit of Detection 7 8358
. Missing 904 9262

LBXCBC - cis-b-carotene(ug/dL)

Variable Name:
LBXCBC
SAS Label:
cis-b-carotene(ug/dL)
English Text:
cis-b-carotene(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.7 to 13.6 Range of Values 4025 4025
0.49 Fill Value of Limit of Detection 4334 8359
. Missing 903 9262

LBDCBCSI - cis-b-carotene(umol/L)

Variable Name:
LBDCBCSI
SAS Label:
cis-b-carotene(umol/L)
English Text:
cis-b-carotene(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.013 to 0.253 Range of Values 4025 4025
0.009 Fill Value of Limit of Detection 4334 8359
. Missing 903 9262

LBXCRY - b-cryptoxanthin(ug/dL)

Variable Name:
LBXCRY
SAS Label:
b-cryptoxanthin(ug/dL)
English Text:
b-cryptoxanthin(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.9 to 208.6 Range of Values 8305 8305
0.64 Fill Value of Limit of Detection 12 8317
. Missing 945 9262

LBDCRYSI - b-cryptoxanthin(umol/L)

Variable Name:
LBDCRYSI
SAS Label:
b-cryptoxanthin(umol/L)
English Text:
b-cryptoxanthin(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.016 to 3.776 Range of Values 8305 8305
0.012 Fill Value of Limit of Detection 12 8317
. Missing 945 9262

LBXGTC - g-tocopherol(ug/dL)

Variable Name:
LBXGTC
SAS Label:
g-tocopherol(ug/dL)
English Text:
g-tocopherol(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
18 to 1977 Range of Values 8307 8307
8 Fill Value of Limit of Detection 1 8308
. Missing 954 9262

LBDGTCSI - g-tocopherol(umol/L)

Variable Name:
LBDGTCSI
SAS Label:
g-tocopherol(umol/L)
English Text:
g-tocopherol(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.432 to 47.488 Range of Values 8307 8307
0.192 Fill Value of Limit of Detection 1 8308
. Missing 954 9262

LBXLUZ - Combined Lutein/zeaxanthin(ug/dL)

Variable Name:
LBXLUZ
SAS Label:
Combined Lutein/zeaxanthin(ug/dL)
English Text:
Combined Lutein/zeaxanthin(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2.5 to 85 Range of Values 8342 8342
1.7 Fill Value of Limit of Detection 11 8353
. Missing 909 9262

LBDLUZSI - Combined Lutein/zeaxanthin(umol/L)

Variable Name:
LBDLUZSI
SAS Label:
Combined Lutein/zeaxanthin(umol/L)
English Text:
Combined Lutein/zeaxanthin(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.044 to 1.494 Range of Values 8342 8342
0.03 Fill Value of Limit of Detection 11 8353
. Missing 909 9262

LBXLYC - trans-lycopene(ug/dL)

Variable Name:
LBXLYC
SAS Label:
trans-lycopene(ug/dL)
English Text:
trans-lycopene(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.8 to 79.8 Range of Values 8336 8336
0.57 Fill Value of Limit of Detection 12 8348
. Missing 914 9262

LBDLYCSI - trans-lycopene(umol/L)

Variable Name:
LBDLYCSI
SAS Label:
trans-lycopene(umol/L)
English Text:
trans-lycopene(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.015 to 1.487 Range of Values 8336 8336
0.011 Fill Value of Limit of Detection 12 8348
. Missing 914 9262

LBXRPL - Retinyl palmitate(ug/dL)

Variable Name:
LBXRPL
SAS Label:
Retinyl palmitate(ug/dL)
English Text:
Retinyl palmitate(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.2 to 72.7 Range of Values 7885 7885
0.14 Fill Value of Limit of Detection 168 8053
. Missing 1209 9262

LBDRPLSI - Retinyl palmitate(umol/L)

Variable Name:
LBDRPLSI
SAS Label:
Retinyl palmitate(umol/L)
English Text:
Retinyl palmitate(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.007 to 2.538 Range of Values 7885 7885
0.005 Fill Value of Limit of Detection 168 8053
. Missing 1209 9262

LBXRST - Retinyl stearate(ug/dL)

Variable Name:
LBXRST
SAS Label:
Retinyl stearate(ug/dL)
English Text:
Retinyl stearate(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.5 to 29.8 Range of Values 1073 1073
0.35 Fill Value of Limit of Detection 7033 8106
. Missing 1156 9262

LBDRSTSI - Retinyl stearate(umol/L)

Variable Name:
LBDRSTSI
SAS Label:
Retinyl stearate(umol/L)
English Text:
Retinyl stearate(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.017 to 1.04 Range of Values 1073 1073
0.012 Fill Value of Limit of Detection 7033 8106
. Missing 1156 9262

LBXVIA - Retinol(ug/dL)

Variable Name:
LBXVIA
SAS Label:
Retinol(ug/dL)
English Text:
Retinol(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.4 to 182.1 Range of Values 8365 8365
. Missing 897 9262

LBDVIASI - Retinol(umol/L)

Variable Name:
LBDVIASI
SAS Label:
Retinol(umol/L)
English Text:
Retinol(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.049 to 6.357 Range of Values 8365 8365
. Missing 897 9262

LBXVIE - a-tocopherol(ug/dL)

Variable Name:
LBXVIE
SAS Label:
a-tocopherol(ug/dL)
English Text:
a-tocopherol(ug/dL)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
75.3 to 13083.9 Range of Values 8365 8365
. Missing 897 9262

LBDVIESI - a-tocopherol(umol/L)

Variable Name:
LBDVIESI
SAS Label:
a-tocopherol(umol/L)
English Text:
a-tocopherol(umol/L)
Target:
Both males and females 3 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.748 to 303.808 Range of Values 8365 8365
. Missing 897 9262