How Much Sodium Per Day and the Recommended Limit

Short answer: The NIH Office of Dietary Supplements sets the Adequate Intake (AI) for sodium at 1,500 mg per day for adults. A separate threshold called the Chronic Disease Risk Reduction Intake (CDRR) is set at 2,300 mg per day, meaning adults who regularly consume more than that amount are advised to reduce intake to lower long-term cardiovascular risk.

What Is Sodium and Why Does the Body Need It?

Sodium is an essential mineral, meaning the body cannot make it and must obtain it from food. According to the NIH Office of Dietary Supplements, sodium serves three core physiological roles.

• Membrane potential: Sodium helps maintain the electrochemical gradient across cell membranes through the sodium-potassium (Na+/K+) ATPase pump. This process is estimated to account for 20 to 40 percent of resting energy expenditure, making it one of the most energy-demanding functions in the body.
• Fluid balance and blood pressure regulation: Sodium controls extracellular fluid volume and, working alongside the kidneys and hormones, helps regulate blood pressure.
• Nerve and muscle function: Sodium supports normal nerve impulse transmission and muscle contraction.

Sodium is essential and safe at normal dietary amounts. Deficiency from low intake alone is rare in healthy people eating a varied diet.

The Recommended Daily Intake

The 2019 National Academies of Sciences, Engineering, and Medicine (NASEM) Dietary Reference Intake (DRI) report, which informs NIH Office of Dietary Supplements guidance, established the following reference values for adults.

• Adequate Intake (AI): 1,500 mg per day. This is the target intake considered sufficient to meet the needs of healthy adults.
• Chronic Disease Risk Reduction Intake (CDRR): 2,300 mg per day. Adults who habitually consume above this level are advised to reduce intake to lower long-term cardiovascular risk. Importantly, the 2019 NASEM report replaced the previous Tolerable Upper Intake Level (UL) with this CDRR designation. No traditional UL has been set for sodium.

These are population-level reference values. Your personal target may differ based on health status, medications, or medical history. Always consult a clinician for guidance specific to your situation.

What the Evidence Says About Sodium and Cardiovascular Health

The NIH Office of Dietary Supplements grades the strength of evidence for sodium-related health outcomes as follows.

Blood Pressure (Strong Evidence)

Higher dietary sodium intake raises blood pressure, and reducing sodium lowers blood pressure in people with elevated readings. This relationship is graded as strong by the evidence review underpinning NIH guidance. Because high blood pressure is a major risk factor for heart disease and stroke, this finding is the primary reason health agencies recommend staying within the CDRR.

Cardiovascular Morbidity and Mortality (Limited Evidence)

Moderate sodium restriction is associated with reduced cardiovascular morbidity and mortality, but this evidence is graded as limited. This means the signal is present but the research base is not yet large or consistent enough to draw firm conclusions independent of the blood pressure data.

Salt Sensitivity (Moderate Evidence)

Blood pressure response to sodium varies considerably between individuals, a phenomenon called salt sensitivity. Evidence for this individual variation is graded as moderate. Factors such as age, kidney function, and genetic background can influence how strongly a person's blood pressure responds to changes in sodium intake.

Sodium Supplementation During Exercise (Insufficient Evidence)

There is insufficient evidence that sodium supplementation provides benefits to people beyond replacing losses during prolonged, intense exercise. This grading means the current research cannot support broader claims about performance or recovery benefits from sodium supplements in the general population.

Please note: supplements are not intended to diagnose, treat, cure, or prevent any disease, and these statements have not been evaluated by the FDA.

Medications That Interact With Sodium

Sodium intake and sodium levels in the body can interact meaningfully with several common medications. Talk to a doctor or pharmacist before combining sodium supplements with any medication.

• Diuretics: Loop and thiazide diuretics increase urinary sodium loss and can contribute to low blood sodium (hyponatremia). Potassium-sparing diuretics affect the sodium-potassium balance in a different way.
• Lithium: Low sodium intake, or sodium loss from diuretics, sweating, or vomiting, reduces lithium clearance and can raise lithium blood levels toward toxicity. Conversely, an abrupt increase in sodium can lower lithium levels and reduce its therapeutic effect.
• Corticosteroids and mineralocorticoid-active drugs: These medications promote sodium and fluid retention, which can compound the effects of a high-sodium diet.
• NSAIDs and antihypertensive drugs (including ACE inhibitors and ARBs): High sodium intake can blunt the blood-pressure-lowering effects of these medications, and these agents can also alter how the kidneys handle sodium and potassium.

Common Dietary Sources of Sodium

Most sodium in the typical diet does not come from table salt added at home. Processed and packaged foods, restaurant meals, breads, cured meats, canned goods, and condiments are the dominant contributors. Reading the Nutrition Facts label is the most reliable way to track sodium intake from packaged products. The FDA provides sodium reduction guidance and labeling resources at fda.gov.

Key Takeaways

• The NIH Office of Dietary Supplements sets the adult AI for sodium at 1,500 mg per day.
• The CDRR is 2,300 mg per day. Consuming above this level is associated with increased long-term cardiovascular risk, and reduction is advised.
• No traditional Tolerable Upper Intake Level exists for sodium. The CDRR replaced it in the 2019 NASEM DRI report.
• Strong evidence links higher sodium intake to higher blood pressure and shows that reducing sodium lowers blood pressure in people with elevated readings.
• Evidence for broader cardiovascular mortality benefits from sodium restriction is limited, and evidence for sodium supplementation benefits beyond exercise-related loss replacement is insufficient.
• Several medications interact with sodium status, including diuretics, lithium, corticosteroids, NSAIDs, and antihypertensives.
• These are population reference values. Consult a clinician or pharmacist to determine what is appropriate for your individual health needs.