Association of Total, Added, and Natural Phosphorus Intakes with Biomarkers of Health Status and Mortality in Healthy Adults in the United States

The Western diet is high in dietary phosphorus, partially due to added phosphorus, (i.e., phosphates) predominantly present in processed food products. Elevated serum phosphate levels, otherwise known as hyperphosphatemia, have been associated with changes in health status, of note detrimental effects on cardiovascular and renal health. However, the extent to which highly absorbed added phosphorus contributes to these changes is relatively unknown, due to its poor characterization among food composition databases. Industry-provided data on phosphorus source ingredients and ranges of added phosphorus present in food categories to enable a more accurate estimation of the total, added, and natural phosphorus intakes in the U.S. population. Using regression analyses, we then assessed relationships between estimated total, added, and natural phosphorus intakes on biomarkers of health status and mortality in individuals enrolled in the National Health and Nutrition Examination Survey (NHANES) 1988-1994 and 2001-2016 datasets. Total, added, and natural phosphorus intakes were associated with several biomarkers of health status. Added phosphorus intake was consistently inversely associated with HDL cholesterol in both men and women, whereas naturally occurring phosphorus intake was inversely correlated with the risk of elevated blood pressure. However, in most cases, the predicted impact of increases in phosphorus intake would result in small percentage changes in biomarkers. No meaningful associations between phosphorus and mortality were found, but indications of a correlation between mortality with quintiles of naturally occurring phosphorus were present, depending on covariate sets used. The disparate results for natural and added phosphorus intakes within the current study provide increased support for updating current food composition databases to more accurately account for dietary phosphorus intake as total, naturally occurring, and added phosphorus.