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Providing perspectives on recent research into vitamins and nutritionals


Serum Carotenoids and Perspective on the Alpha-Tocopherol Beta-Carotene (ATBC) Study

By Michael McBurney

Carotenoids are yellow, orange, and red pigments found in plants. Out of over 600 carotenoids found in nature, only six, i.e. β-carotene, lycopene, lutein, zeaxanthin, α-carotene, β-cryptoxanthin, are absorbed in quantity into the body. Only three (β-carotene, α-carotene and β-cryptoxanthin) can be converted to vitamin A in the body. Lutein and zeaxanthin are highly concentrated in the macular pigment of the retina, playing an important role in vision. Lutein supplementation increases visual function in adults.  Emerging science links lutein status with cognitive function.

Because serum carotenoids have been inversely associated with cardiovascular disease (CVD) risk, Wang and colleagues assessed carotenoid intakes (2-24h recalls) and serum carotenoid concentrations measured in 2,856 adults participating in NHANES 2003-2006. While significant correlations between dietary carotenoid intake and CVD risk factors were observed,  most of the statistical associations became null after adjusting for serum concentrations. This indicates that nutrient-health relationships are a function of nutrient status . Once again, it indicates the importance of using biomarkers, rather than dietary intake estimates, to determine nutrient-structure/function relationships.

Wang and associates do not report serum carotenoid concentrations but these are available from the CDC Second Nutrition Report for NHANES 2003-2006.





β-carotene, µg/dL




β-cryptoxanthin, µg/dL




Lutein/zeaxanthin, µg/dL




Trans-Lycopene, µg/dL




α-carotene, µg/dL




The CDC data demonstrates that US adults have lower serum carotenoid levels than US children (reported yesterday). In essence, adults are worse than children when it comes to eating adequate amounts of carotenoid-rich foods.

The Journal of Nutrition study is a prompt to put the results of the Alpha-Tocopherol  Beta-Carotene (ATBC) Prevention study  into perspective. The ATBC participants did not reflect the general population. The control participants in the ATBC study had average baseline concentrations of  ~20 µg/dL. The intervention group reached pharmacologic levels (~319 µg/dL).  The participants in the ATBC study are not typical of the general population. Their participation in the study indicates an interest in nutrition. Their serum carotenoid concentrations indicates an unusual willingness to eat carotenoid-rich foods or use carotenoid supplements.

Today’s main citation is important for three reasons. First, it affirms the importance of using biomarker data rather than food intake data to elucidate nutrient-disease relationships. Second, it demonstrates that carotenoid status of most people is very poor. Third, results from nutrient intervention studies which were conducted in well-nourished individuals with pharmacologic doses should not be extrapolated to the general population.

Main Citation

Wang Y, Chung S-J, McCullough ML, Song WO, Fernandez ML, Koo SI, Chun OK. Dietary carotenoids are associated with cardiovascular disease risk biomarkers mediated by serum carotenoid concentrations. 2014 J Nutr doi: 10.3945/jn.113.184317

Other Citations

Renzi LM, Bovier ER, Hammond BR. A role for the macular carotenoids in visual motor response. 2013 Nutr Neuroscidoi:10.1179/1476830513Y.000000054

Johnson E. A possible role for lutein and zeaxanthin in cognitive function in the elderly. 2012 Am J Clin Nutr doi:10.3945/ajcn.112.034611

Albanes D, Virtano J, Taylor PR, Rautalahti M, Pietinen P, Heinonen OP. Effects of supplemental β-carotene, cigarette smoking, and alcohol consumption on serum carotenoids in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. 1997 Am J Clin Nutr 66:366-372