Nutriets are required to maintain life, support basic physiological functions, and prevent deficiencies.
Nutrients are essential if they cannot be synthesized by the body and if a deficiency causes recognizable abnormalities that disappear when the deficit is corrected.
Required nutrients include the essential amino acids, water-soluble vitamins, fat-soluble vitamins, minerals, and the essential fatty acids.
Basic Dietary Requirements represent what your body needs at rest (before considering illness, stress, or increased activity).
{How can these automatically calculated for a given patient USE AI]
Needed to fuel the body’s basal metabolic rate (BMR), thermoregulation, and daily activity.
Average daily needs (can vary with age, sex, weight, and activity):
Adult women: ~1,600–2,400 kcal/day
Adult men: ~2,000–3,000 kcal/day
| Requirement | Daily Requirement | Notes |
|---|---|---|
| Energy | Women: 1,600–2,400 kcalMen: 2,000–3,000 kcal | Depends on age, size, and activity level |
Carbohydrates:
Main energy source for brain and muscles.
Baseline: ~45–65% of daily calories (~130 g/day minimum for brain glucose needs).
For energy, fat-soluble vitamin absorption, hormone production, and cell membranes.
Baseline: ~20–35% of daily calories, with essential fatty acids (omega-3, omega-6).
| Dietrary Requirement | Daily Requirement | Notes |
|---|---|---|
| Carbohydrates | 45–65% of calories(≥130 g/day minimum) | Primary energy source, especially for brain |
| Protein | 0.8 g/kg body weight (~46 g women, ~56 g men) | Higher if ill, elderly, or active |
| Fat (total) | 20–35% of calories | Include essential fatty acids |
| • Omega-6 (linoleic acid) | Women: 12 gMen: 17 g | Vegetable oils, nuts, seeds |
| • Omega-3 (ALA) | Women: 1.1 gMen: 1.6 g | Flax, walnuts, fatty fish |
| Fiber | Women: 25 gMen: 38 g | Whole grains, fruits, vegetables |
| Water | Women: 2.7 LMen: 3.7 L | From fluids + food combined |
Vital for all biochemical reactions, temperature regulation, and waste removal.
Baseline: ~2.7 liters/day (women), ~3.7 liters/day (men), from fluids + food
| Dietrary Requirement | Daily Requirement | Notes |
|---|---|---|
| Fiber | Women: 25 gMen: 38 g | Whole grains, fruits, vegetables |
| Water | Women: 2.7 LMen: 3.7 L | From fluids + food combined |
Vitamins include fat-soluble vitamins (A, D, E, K) and water-soluble vitamins (B-complex and C).
e.g., Vitamin A (vision, immunity), Vitamin D (bone health), Vitamin C (collagen, antioxidant), B-complex (energy metabolism).
Each plays specific roles in metabolism, immune function, and cellular processes.
Minerals: e.g., Calcium (bones, muscle contraction), Iron (hemoglobin), Magnesium (enzymes, muscles), Zinc (wound healing), Sodium/Potassium (electrolytes, nerve signals).oxygen transport, muscle function, and countless enzymatic reactions.
Baseline: ~25 g/day (women), ~38 g/day (men).
Fiber supports digestive health and helps regulate blood sugar and cholesterol.
Here’s a concise table of the baseline daily nutritional needs for a healthy adult (based on U.S. Dietary Guidelines and WHO recommendations):
| Vitamin | Daily Requirement | Function |
|---|---|---|
| A | 700 µg (women), 900 µg (men) | Vision, immunity |
| D | 600 IU (15 µg) | Bone health, immunity |
| E | 15 mg | Antioxidant |
| K | 90 µg (women), 120 µg (men) | Blood clotting |
| C | 75 mg (women), 90 mg (men) | Collagen, immunity |
| B1 (Thiamine) | 1.1 mg (women), 1.2 mg (men) | Energy metabolism |
| B2 (Riboflavin) | 1.1 mg (women), 1.3 mg (men) | Energy metabolism |
| B3 (Niacin) | 14 mg (women), 16 mg (men) | Metabolism, skin, nerves |
| B6 | 1.3–1.7 mg | Amino acid metabolism |
| B12 | 2.4 µg | Nerve health, red blood cells |
| Folate | 400 µg | DNA synthesis, pregnancy health |
| Mineral | Daily Requirement | Function |
|---|---|---|
| Calcium | 1,000 mg | Bones, nerves, muscles |
| Iron | 18 mg (women), 8 mg (men) | Hemoglobin, energy |
| Magnesium | 310–320 mg (women), 400–420 mg (men) | Enzymes, muscles |
| Potassium | 2,600 mg (women), 3,400 mg (men) | Fluid balance, heart |
| Sodium | ≤2,300 mg (ideal <1,500 mg) | Fluid balance, nerves |
| Zinc | 8 mg (women), 11 mg (men) | Wound healing, immunity |
| Phosphorus | 700 mg | Energy, bones |
| Iodine | 150 µg | Thyroid function |
| Selenium | 55 µg | Antioxidant |
Requirements can change with age, sex, pregnancy, illness, or activity level.
Individual needs can differ substantially from general recommendations, which is why personalized nutrition approaches are often most effective.
Nutritional requirements have been expressed most commonly by recommended dietary allowances (RDAs). Published and periodically reviewed by the Food and Nutrition Board of the National Academy of Sciences, the RDAs were initially designed to meet the known nutritional needs of people without significant health complications. RDAs have been established for carbohydrate and protein; the water-soluble vitamins thiamine, riboflavin, niacin, vitamin B6, folate, vitamin B12, and vitamin C; the fat-soluble vitamins A, D, E and K; and the minerals copper, phosphorus, magnesium, iron, zinc, iodine, molybdenum, and selenium.