Introduction

Postural Orthostatic Tachycardia Syndrome (POTS) is a form of autonomic dysfunction that causes an excessive increase in heart rate when standing. Managing this condition can be complex, and one strategy often recommended by healthcare professionals is increasing sodium intake. But how effective is this approach?

A clinical study, “Effect of High Dietary Sodium Intake in Patients With Postural Tachycardia Syndrome”, published in the Journal of the American College of Cardiology (Garland et al., 2021) explored the physiological impact of high versus low sodium intake in individuals with POTS. The findings provide strong evidence for the benefits of higher sodium consumption—especially in terms of blood volume and heart rate regulation.

Understanding POTS and Circulatory Regulation

POTS is marked by an abnormal cardiovascular response to standing. When a person with POTS stands, blood pools in the lower extremities due to insufficient vasoconstriction, which reduces blood returning to the heart and brain. To compensate, the heart speeds up excessively, resulting in a significant increase in heart rate.

One key factor contributing to this response is low plasma volume. Sodium helps the body retain water and expand plasma volume, potentially improving cardiovascular stability in upright posture.

Study Objective

The goal of the study by Garland et al. (2021) was to determine how different levels of dietary sodium affect:

• Plasma volume
  

• Orthostatic heart rate
  

• Plasma norepinephrine levels
  
  

The hypothesis: A high-sodium diet would improve volume status and reduce the exaggerated cardiovascular response seen in POTS.

Methodology

The study included:

• 14 female patients with POTS and 13 healthy controls, aged 23–49.
  

• Each POTS patient completed two 6-day dietary interventions in random order:
  

• Low Sodium (LS): 10 mEq/day (~230 mg/day)
  

• High Sodium (HS): 300 mEq/day (~6,900 mg/day)
  

What was measured:

• Plasma volume
  

• Supine and upright heart rate and blood pressure
  

• Plasma norepinephrine levels (as a marker of sympathetic activation)
  

Key Findings

“Effect of High Dietary Sodium Intake in Patients With Postural Tachycardia Syndrome” (Garland et al., 2021) revealed clear physiological differences between the high and low sodium intake periods in POTS patients:

 1. Increased Plasma Volume

• The high-sodium diet led to a significant increase in plasma volume.
  

• This improvement suggests better volume support for circulatory function when upright.
  

 2. Reduced Orthostatic Tachycardia

• Standing heart rate and orthostatic heart rate change (ΔHR) were significantly lower with the high-sodium diet.
  

• The exaggerated heart rate response to standing was partially normalized.
  

 3. Lower Standing Norepinephrine

• Plasma norepinephrine levels—typically elevated in POTS—were reduced on the high-sodium diet, indicating reduced sympathetic overactivation.

Note:

Despite improvements, POTS patients still had elevated heart rate and norepinephrine levels compared to healthy controls, even after the high-sodium intervention.

Conclusions

According to Garland et al. (2021), “Patients with POTS experienced decreases in heart rate, supine and upright heart rate, and standing plasma norepinephrine following a short-term period of dietary sodium intake of 300 mEq/day compared with a period of 10 mEq sodium/day. The deficit in PV evident in previous studies and in the LS phase of this study was eliminated by an HS diet, suggesting that the restoration of PV contributed to improvement, although not normalization, in POTS. This study provides solid data to support the recommendations for increased dietary sodium intake in POTS.”

This information states that a high dietary sodium intake improves key physiological markers in patients with POTS. Specifically, it:

• Increases plasma volume
  

• Reduces standing heart rate
  

• Lowers sympathetic nervous system activity (as measured by norepinephrine)

These changes may contribute to better cardiovascular stability in individuals with POTS. While the study didn’t assess subjective symptom changes, the physiological improvements observed support the clinical practice of recommending increased sodium intake as part of POTS management.

Clinical Implications & Klaralyte's Role

While the study does not explore specific sodium sources, it highlights the importance of reaching adequate sodium levels—close to 6,900 mg/day in the high-sodium condition. For many patients, achieving that through diet alone is difficult, which is where sodium supplementation becomes useful.

At Klaralyte, we provide first-in-quality salt capsules formulated to support patients with dysautonomia and POTS. Each capsule contains:

• 250 mg sodium & 50 mg potassium
  

• Only 3 ingredients: Sodium chloride, potassium citrate and a vegetarian capsule
  

• No additives and no hidden ingredients

• Value size savings (only $0.09 per capsule)

Note: Klaralyte was not evaluated in this study. Patients should consult their healthcare provider before making changes to their sodium intake.

Final Thoughts

The study by Garland et al. provides valuable insight into how sodium affects cardiovascular physiology in some POTS patients. By increasing sodium intake under medical supervision, patients may benefit from:

• Better blood volume regulation
  

• Reduced orthostatic heart rate response
  

• Less sympathetic nervous system activation
  

These physiological improvements support the use of sodium as a key tool in POTS management—when used correctly and consistently.

Learn more about Klaralyte’s Salt Capsules

Try Klaralyte’s Big Bag (1,000ct) today!

Source: Garland, Emily M., Alfredo Gamboa, Victor C. Nwazue, Jorge E. Celedonio, Sachin Y. Paranjape, Bonnie K. Black, Luis E. Okamoto, et al. 2021. «Effect Of High Dietary Sodium Intake In Patients With Postural Tachycardia Syndrome». Journal Of The American College Of Cardiology 77 (17): 2174-84. https://doi.org/10.1016/j.jacc.2021.03.005.