From the Guidelines
The daily dose of caffeine for healthy adults should not exceed 400 milligrams, as recommended by the most recent guidelines 1, 2. This is roughly equivalent to four 8-ounce cups of brewed coffee, 10 cans of cola, or two energy shot drinks.
Key Considerations
- Pregnant women should limit their intake to 200 milligrams per day, while adolescents should consume no more than 100 milligrams daily, as advised by the DGA 2.
- Children under 12 should avoid caffeine altogether due to potential adverse effects on their developing bodies.
- Individual sensitivity to caffeine varies, so some people may need to consume less to avoid side effects such as insomnia, jitteriness, increased heart rate, headaches, and anxiety.
- It's best to avoid caffeine at least 6 hours before bedtime to prevent sleep disruption.
- People with certain medical conditions like heart problems, high blood pressure, or anxiety disorders should consult with their healthcare provider about appropriate caffeine limits, as these conditions may be exacerbated by caffeine consumption 1, 2.
Rationale
The recommended daily dose of caffeine is based on the latest guidelines from the Dietary Guidelines for Americans (DGA) 1, 2, which suggest that healthy adults can safely consume up to 400 milligrams of caffeine per day.
Important Notes
- Decaffeinated coffee and tea can also serve as healthy beverage choices because the phenolic acids and flavonoids associated with health benefits are present in these products, although modestly reduced in amounts 2.
- When consuming coffee and tea, it's essential to account for nutrients and calories from dairy, added sugars, and additions within the overall diet, as these can significantly impact overall health 1, 2.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Prior to initiation of caffeine citrate, baseline serum levels of caffeine should be measured in infants previously treated with theophylline, since preterm infants metabolize theophylline to caffeine Likewise, baseline serum levels of caffeine should be measured in infants born to mothers who consumed caffeine prior to delivery, since caffeine readily crosses the placenta. The recommended loading dose and maintenance doses of caffeine citrate follow using a syringe infusion pump † beginning 24 hours after the loading dose Dose of Caffeine Citrate Dose of Caffeine Citrate Route Frequency Volume mg/kg Loading Dose 1 mL/kg 20 mg/kg Intravenous One Time (over 30 minutes) Maintenance 0. 25 mL/kg 5 mg/kg Intravenous* Every Dose (over 10 24 hours† minutes) or Orally NOTE THAT THE DOSE OF CAFFEINE BASE IS ONE-HALF THE DOSE WHEN EXPRESSED AS CAFFEINE CITRATE (e.g., 20 mg of caffeine citrate is equivalent to 10 mg of caffeine base).
The accepted daily dose of caffeine is 20 mg/kg as a loading dose and 5 mg/kg as a maintenance dose for infants, with the dose of caffeine base being one-half the dose when expressed as caffeine citrate 3.
From the Research
Accepted Daily Dose of Caffeine
The accepted daily dose of caffeine varies among different populations.
- For healthy adults, the daily dose is up to 400 mg day(-1) [(4, 5, 6, 7, 8)].
- For reproductive-aged women, the daily dose should be <=300 mg [(4, 6)].
- For children, the daily dose should be <=2.5 mg kg(-1) bw day(-1) 4 or <=45 mg/day for young children age 4-6 years 5.
- Pregnant women should limit caffeine intake to no more than 300 mg/d [(6, 7)].
Factors Influencing Caffeine Intake
Several factors can influence caffeine intake, including:
- Age: children, adolescents, and the elderly may be more vulnerable to the adverse effects of caffeine [(6, 7)].
- Pregnancy: caffeine metabolism is slowed down in pregnant women, and caffeine can pass freely across the placenta into the fetus 7.
- Lifestyle: individual metabolism of caffeine depends on many endogenic and environmental factors 7.
- Sources of caffeine: coffee, tea, and soft drinks are the most important caffeine sources 8.