NUTRIENT | Amount stored in the body - assuming adequate intake | ADULT RNI |
Calcium | Approx 1.2kg mostly in bones and teeth. Plasma concentration is tightly controlled, with the skeleton acting as a reserve store. | 700mg/day
More in adolescent females |
Magnesium | Approx 25g, 60% in the skeleton, 27% in muscles and remainder in other cells and tissues. Plasma concentration is tightly controlled, with the skeleton acting as a reserve store. | Females 270mg/day
Males 300mg/day |
Phosphate | Approx 1.1kg, 80% found in the skeleton and remainder in cells and tissues. Deficiency rare. | 550mg/day |
Sodium | Approx 100g, 37% in bone tissue, majority found in cells and tissue fluid. Deficiency rare. | 1,600mg/day |
Potassium | 110-135g, 95% found inside cells, 5% outside. Deficiency rare. | 3,500mg/day |
Chloride | Approx 1.2g/kg body weight in males, 70% in extra cellular fluid, the remainder within cells, connective tissue and bone. | Intakes to correspond with sodium |
Chromium | Undefined amount, mostly in conjunction with insulin and nucleic acids. | Safe intake above 25µg/day |
Copper | Approx 100-120mg, stored mainly in liver, brain, kidneys, heart and hair. Deficiency rare. | 1.2mg/day |
Fluoride | Undefined amount, stored as calcium fluorapatite in teeth and bone. | No RNI as in drinking water; no more than 0.05mg /kg body weight /day in children |
Iodine | Approx 15-20mg, 80% in thyroid gland as thyroxine (T4) or triiodothyronin (T3). Deficiency rare in UK. | 140µg/day |
Iron | Approx 4kg in males, 2.1kg in females, 60% carried as haemoglobin and remainder stored in liver, spleen, bone marrow and muscles (myoglobin). | Females 14.8mg/day
Males 8.7mg/day |
Manganese | Approx 10-20mg, 25% is found in bone, remainder in other tissues as a component of enzymes. | Adequate intake 1.8-2.3mg/day |
Molybdenum | Undefined. | Safe intake 50-400µ/day |
Selenium | Approx 30mg, but depends on geographical location. Found in all tissues, bound to amino acids and proteins. Regular intake needed to maintain adequate reserves. | Females 60µg/day
Males 75µg/day |
Zinc | Approx 2-3g, 60% found in skeletal muscles, 30% in bone, 4-6% in skin and remainder found inside cells. Not easily mobilised from reserves and regular intake is important. | Females 7mg/day
Males 9.5mg/day |