Recommended Daily Allowances (RDA) are the estimated amount of a nutrient (or calories) per day considered necessary for the maintenance of good health by the Food and Nutrition Board of the National Research Council/ National Academy of Sciences. In practice, these are arguably the minimum levels required to avoid acute deficiency diseases (like scurvy or rickets).
Optimal Ranges, often cited by longevity researchers and functional medicine practitioners, aim for levels associated with peak biological performance, lowest all-cause mortality, and long-term vitality. These values may be higher than RDAs to support processes like DNA repair, optimal hormone production, and neurological health.
A comprehensive reference comparing government recommended daily allowances (RDA) with optimal functional health ranges.
* Values are for general reference only. Consult a physician for personal needs.
| Nutrient | US RDA | EU RDA | Optimal Range | Upper Limit | Notes |
|---|---|---|---|---|---|
Vitamin A (Retinol) Vitamin | 900 mcg (3000 IU) | 800 mcg | 3000 - 5000 IU | 3000 mcg (10,000 IU) | Fat-soluble. Essential for vision and immune function. |
Vitamin C (Ascorbic Acid) Vitamin | 90 mg | 80 mg | 500 - 1000 mg | 2000 mg | Water-soluble antioxidant. Immune support, collagen synthesis. |
Vitamin D3 Vitamin | 15-20 mcg (600-800 IU) | 5 mcg (200 IU) | 2000 - 5000 IU | 100 mcg (4000 IU)* | Fat-soluble. *Upper limit debated, toxicity rare below 10k IU/day. Critical for hormones and bone health. |
Vitamin E Vitamin | 15 mg (22.4 IU) | 12 mg | 100 - 400 IU | 1000 mg (1500 IU) | Fat-soluble antioxidant. Protects cell membranes. |
Vitamin K1 (Phylloquinone) Vitamin | 120 mcg | 75 mcg | 100 - 200 mcg | - | Blood clotting. Comparison to K2 is important. |
Vitamin K2 (Menaquinone) Vitamin | Not Established | Not Established | 100 - 200 mcg | - | Crucial for directing calcium to bones/teeth and away from arteries. |
Vitamin B1 (Thiamine) Vitamin | 1.2 mg | 1.1 mg | 25 - 50 mg | - | Energy metabolism, nerve function. |
Vitamin B2 (Riboflavin) Vitamin | 1.3 mg | 1.4 mg | 25 - 50 mg | - | Energy production, cellular function. |
Vitamin B3 (Niacin) Vitamin | 16 mg | 16 mg | 25 - 50 mg | 35 mg (Flushing) | DNA repair, energy. Upper limit refers to flushing sensation. |
Vitamin B5 (Pantothenic Acid) Vitamin | 5 mg | 6 mg | 50 - 100 mg | - | Coenzyme A synthesis. |
Vitamin B6 (Pyridoxine) Vitamin | 1.3 - 1.7 mg | 1.4 mg | 10 - 25 mg | 100 mg | Neurotransmitter synthesis. P5P form is preferred. |
Vitamin B7 (Biotin) Vitamin | 30 mcg | 50 mcg | 1000 - 5000 mcg | - | Hair, skin, nail health. Can interfere with thyroid lab tests. |
Vitamin B9 (Folate) Vitamin | 400 mcg | 200 mcg | 400 - 800 mcg | 1000 mcg | Methylation, DNA synthesis. Methylfolate is preferred over folic acid. |
Vitamin B12 (Cobalamin) Vitamin | 2.4 mcg | 2.5 mcg | 100 - 500 mcg | - | Nerve health, energy. Methylcobalamin form preferred. |
Calcium Mineral | 1000 mg | 800 mg | 800 - 1200 mg | 2500 mg | Bone health. Balance with Magnesium and K2. |
Magnesium Mineral | 400 - 420 mg | 375 mg | 400 - 600 mg | 350 mg (Supplement) | Involved in 300+ enzyme reactions. Glycinate/Threonate/Malate forms preferred over Oxide. |
Zinc Mineral | 11 mg | 10 mg | 15 - 30 mg | 40 mg | Immune system, testosterone. Balance with Copper. |
Iron Mineral | 8 - 18 mg | 14 mg | Varies via Ferritin labs | 45 mg | Men usually need less supplemental iron than women. |
Copper Mineral | 900 mcg | 1 mg | 1 - 2 mg | 10 mg | Balance with Zinc (10:1 ratio Zn:Cu often cited). |
Selenium Mineral | 55 mcg | 55 mcg | 100 - 200 mcg | 400 mcg | Thyroid health, antioxidant. |
Iodine Mineral | 150 mcg | 150 mcg | 150 - 300 mcg | 1100 mcg | Thyroid health. Support with Selenium. |
Potassium Mineral | 4700 mg | 2000 mg | 3500 - 4700 mg | - | Electrolyte balance, blood pressure. |
Sodium Mineral | 1500 mg | Not Established | 3000 - 5000 mg (Active) | 2300 mg (USDA) | Needs increase significantly with exercise/sweating. |
Protein Macronutrient | 0.8 g/kg bodyweight | 0.83 g/kg | 1.6 - 2.2 g/kg | - | Higher intake recommended for muscle retention and satiety. |
Fiber Macronutrient | 38 g (Men), 25 g (Women) | 25 g | 30 - 50 g | - | Gut health, blood sugar regulation. |
Omega-3 (EPA+DHA) Other | Not Established (AI: 1.6g ALA) | 250 mg | 2000 - 3000 mg | - | Anti-inflammatory, brain health. |
Creatine Other | Not Established | Not Established | 3 - 5 g | - | Cognitive function, muscular endurance. |
Choline Vitamin | 550 mg | 400 mg | 500 - 1000 mg | 3500 mg | Liver health, neurotransmitter synthesis (Acetylcholine). |