Sodium and potassium intake patterns in Dominican adults

A recent study analyzed sodium (Na) and potassium (K) intake among Dominican adults, revealing notable dietary trends. Given the high sodium consumption in the Caribbean, researchers aimed to compare sodium and potassium intake using both dietary recall and 24-hour urinary excretion methods.

Study Overview

The study included 69 adults (33 men), who provided a three-day dietary recall focusing on added salt and seasonings. Simultaneously, participants submitted 24-hour urine samples for analysis via the membrane ion-selective electrode technique. Additionally, subjects completed a WHO-PAHO questionnaire assessing their knowledge, attitudes, and behaviors related to dietary salt consumption and health.

Results showed dietary sodium intake varied from 1.0 to 8.3 grams per day, with median dietary and urinary sodium concentrations being comparable (2.7 mmol/d vs. 2.5 mmol/d). However, mean dietary sodium and potassium levels were significantly higher than those excreted in urine:

Sodium: 133.0 ± 59.7 mmol/day (dietary) vs. 103.7 ± 44.5 mmol/day (urinary)

Potassium: 69.0 ± 21.0 mmol/day (dietary) vs. 36 ± 16.3 mmol/day (urinary)

Additionally, the Na-to-K ratio was lower in dietary assessments than in urinary samples (2.0 ± 1.1 mmol/d vs. 3.2 ± 1.6 mmol/d).

Key Findings

Urinary sodium concentration correlated with sex (r = 0.280, p = 0.020) and obesity (r = 0.244, p = 0.043), while urinary potassium levels correlated with sex (r = 0.356, p = 0.003). Interestingly, the Na-to-K urinary ratio was inversely related to age (r = −0.291, p = 0.015).

Sex and obesity accounted for 11% of the variance in urinary sodium concentration, while sex alone explained the variance in urinary potassium levels. The only significant correlation between dietary and urinary concentrations was observed in potassium (r = 0.342, p = 0.004). This relationship remained significant even after adjusting for sex and overweight status, explaining roughly 12% of the data variability.

Health Implications

This study represents the first analysis of sodium and potassium intake in Dominicans using both dietary recall and urinary excretion. The findings suggest that average sodium consumption (2.7 g Na or 6.8 g salt/day) exceeds WHO recommendations (<2.0 g Na/day), while potassium intake (2.06 g/day) falls short of the recommended ≥3.5 g/day.

Additionally, while potassium intake showed some correlation between dietary recall and urinary excretion, sodium intake did not, indicating that dietary recall may not be a fully reliable measure for sodium consumption.

Commentary by SuppBase columnist Alice Winters

This study offers a critical perspective on sodium and potassium consumption in the Dominican Republic, emphasizing the limitations of dietary recall as a tool for measuring true intake. The discrepancy between dietary estimates and urinary excretion highlights a common issue in nutritional research—self-reported data often underestimates actual intake due to recall bias and portion misjudgment.

The elevated sodium levels should raise alarms, given their association with hypertension and cardiovascular diseases. The WHO’s recommended sodium intake is exceeded in this study, mirroring a global public health challenge. Excessive salt consumption is deeply ingrained in dietary habits, particularly in regions where processed and salted foods dominate. The study’s focus on added salt and seasonings suggests an urgent need for educational initiatives to modify cooking and eating practices.

On the flip side, potassium intake remains concerningly low, falling well below the WHO benchmark. Since potassium plays a crucial role in counteracting the hypertensive effects of sodium, this imbalance could further exacerbate the region’s cardiovascular risk. Increasing potassium intake through dietary adjustments—such as promoting potassium-rich foods like bananas, beans, and leafy greens—should be prioritized in public health strategies.

Another key takeaway is the role of sex and obesity in sodium excretion. While men generally have higher sodium excretion levels, obesity also appears to influence sodium metabolism, which aligns with broader research linking excessive sodium retention to metabolic disorders. This raises the question: Should dietary interventions be tailored differently based on gender and weight status?

The inverse relationship between the Na-to-K urinary ratio and age is particularly interesting. Could this suggest that younger individuals are consuming even more sodium relative to potassium than older adults? If so, future dietary interventions may need to target younger populations more aggressively, before habits solidify into lifelong risk factors.

Finally, the study’s reliance on both dietary recall and urinary biomarkers is commendable, reinforcing the idea that single-method nutritional assessments are insufficient. However, given the observed inconsistencies, future research should consider broader sample sizes and alternative biomonitoring methods for greater accuracy.

In conclusion, this study underscores the urgent need for sodium reduction policies and potassium-boosting interventions in the Caribbean. Without a significant dietary shift, the population remains at heightened risk for hypertension and cardiovascular complications. Public health messaging should focus not only on reducing salt intake but also on actively increasing potassium-rich foods to restore balance.