Measuring Population Sodium Intake: A Review of Methods

Abstract

Reduction of population sodium intake has been identified as a key initiative for reduction of Non-Communicable Disease. Monitoring of population sodium intake must accompany public health initiatives aimed at sodium reduction. A number of different methods for estimating dietary sodium intake are currently in use. Dietary assessment is time consuming and often under-estimates intake due to under-reporting and difficulties quantifying sodium concentration in recipes, and discretionary salt. Twenty-four hour urinary collection (widely considered to be the most accurate method) is also burdensome and is limited by under-collection and lack of suitable methodology to accurately identify incomplete samples. Spot urine sampling has recently been identified as a convenient and affordable alternative, but remains highly controversial as a means of monitoring population intake. Studies suggest that while spot urinary sodium is a poor predictor of 24-h excretion in individuals, it may provide population estimates adequate for monitoring. Further research is needed into the accuracy and suitability of spot urine collection in different populations as a means of monitoring sodium intake.

Dietary Approach to Stop Hypertension (DASH) diet and risk of renal function decline and all-cause mortality in renal transplant recipients

“…Since salt intake varies widely in both processed and home‐cooked meals, it is difficult to quantify sodium intake using a FFQ 23. Another strength of the current study is the complete follow‐up.…”

“…Sodium intake was determined based on 24‐hour urinary sodium excretion, which is considered the criterion standard to assess daily sodium intake 23. For each of the components, subjects were classified into sex‐specific quintiles according to their intake.…”

Dairy Food Intake Is Inversely Associated with Risk of Hypertension: The Singapore Chinese Health Study

“…Hence, sodium did not significantly confound the dairy-hypertension association. However, this should be interpreted with caution because dietary assessment tools, such as FFQs, often underestimate sodium intake because of underreporting and inherent difficulties in capturing information about recipes and discretionary salt (28). Milk consumption may also serve as a replacement for a sweetened beverage, which was shown to be adversely associated with hypertension risk (13,29).…”

Relationship between sodium and potassium intake and blood pressure in a sample of overweight adults

“…Greater accuracy of sodium and potassium habitual intake would be obtained from repeated 24-h urinary collections [34]. Dietary assessment remains important as it assists in identifying food sources of sodium and potassium which may be useful in making recommendations in health education [33]. Another limitation is that the current study is a secondary analysis of a randomized controlled trial which was designed to answer a different question from the one addressed in this study and there is a possibility of the analysis being underpowered.…”

“…About 90% of the sodium or potassium consumed is excreted in the urine, thus making it a good indicator of dietary intake [33] provided that a complete 24hr sample can be collected. We ascertained completeness of collections by use of urinary creatinine concentrations.…”