Micronutrients in Health and Disease

Mineral

Biochemical Role/Function

Deficiency Symptoms

Toxicity  Symptoms

Recommended Dietary Allowance or AI (*)

Calcium
(Ca)

Component of teeth and bones; mediates vascular contraction and vaso–dilation, muscle contraction, nerve transmission, and glandular secretion

Reduced bone mass and osteoporosis

Hypercalcemia;  increased risk for kidney stones (with supplements);  milk–alkali syndrome; possible increase in risk for prostate cancer (see Prostate Cancer chapter)

Adults: (*)
Ages 19–50: 1,000 mg
Age 51+: 1,200 mg

Infants/children: (*)
0–6 months: 210 mg
7–12months:  270 mg
1–3 years: 500 mg
4–8 years: 800 mg
9–18 years: 1,300 mg

Pregnancy/lactation:(*)
Age <18: 1,300mg
Age 19+: 1,000 mg

Phosphorus (P)

Component of most biological membranes and nucleotides and nucleic acids; buffering of acid or alkali excesses; temporary storage and transfer of the energy derived from metabolic fuels; activation of many catalytic proteins through phosphorylation

 Anorexia, anemia, muscle weakness, bone pain, rickets and osteomalacia, general debility; may be seen in persons recovering from alcoholic bouts; in diabetic keto–acidosis; in refeeding with calorie–rich sources without paying attention to phosphorus needs; & with AL–containing antacids

Metastatic calcification,
skeletal porosity, interference
with calcium absorption

Adults (ages 19+): 700 mg

Infants/children: (*)
0–6 months: 100 mg
7–12months: 275mg
1–3 years: 460 mg
4–8 years: 500 mg
9–18 years: 1,250 mg

Pregnancy/lactation:
Age <18: 1,250 mg
Age 19+: 700 mg

Magnesium
(Mg)

Required cofactor for over 300 enzymes, including ones involved in anaerobic and aerobic energy generation, glycolysis, and oxidative phosphorylation; DNA and RNA synthesis; activation of adenylate cyclase; sodium, potassium–ATPase activity; has a calcium channel–blocking effect

Hypocalcemia; neuro–muscular hyperexcitability & latent tetany; insulin resistance and impaired insulin secretion

GI disturbance (diarrhea, nausea, abdominal cram–ping, paralytic ileus); more likely to occur with impaired renal function   

Adults:
Ages 19–30
males: 400 mg
females: 310 mg
Ages 31+
males: 420 mg
females: 320 mg

Infants/children: (*)
0–6 months: 30 mg
7–12months: 75 mg
1–3 years: 80 mg
4–8 years: 130 mg
9–13 years: 240 mg
14–18 years: (males) 410 mg
(females) 360 mg

Pregnancy:
Ages <18: 400 mg
Ages 19–30: 350 mg
Ages 31–50: 360mg

Lactation:
Ages <18: 360 mg
Ages 19–30: 310 mg
Ages 31–50: 320 mg

Mineral

 Biochemical role/function

  Deficiency symptoms

Toxicity symptoms

Recommended Dietary Allowance or AI (*)

Potassium(K)

Neural transmission;
muscle contraction, vascular tone

Cardiac arrhythmias; muscle weakness; leg discomfort; extreme thirst; frequent urination; confusion; glucose intolerance, increased blood pressure, increased salt sensitivity, increased risk for kidney stones, increased bone turnover

Fatigue, weak–ness, tingling, numbness, or other unusual sensations; paralysis, palpitations, difficulty breathing; cardiac arrhythmias; GI distress

Adults & children:         
> 14 years of age: (*)   4,700 mg

Infants/children: (*)
0–6 months: 400 mg
7–12months: 700mg
1–3 years: 3,000 mg
4–8 years: 3,800 mg
9–13 years: 4,500 mg

Pregnancy:(*)  4,700 mg
Lactation:(*) 5,100 mg

Sodium
(Na)

Maintenance of extra–cellular volume and plasma osmolality; is an important determinant of the membrane potential of cells and the active transport of molecules across cell membranes

Brain swelling, resulting in loss of appetite, nausea, vomiting, headache, mental status changes (confusion, irritability, fatigue, hallucinations); muscle weakness, convulsions

Elevated blood pressure; increased risk for cardiovascular disease and stroke;  neuro–logic symptoms (confusion, coma, paralysis of the lung muscles)

Adults: 19–50 years: (*) 1,500 mg
51–70 years: 1,300 mg
70+ years: 1,200 mg

Infants/children: (*)
0–6 months: 120 mg
7–12months: 370mg
1–3 years: 1,000 mg
4–8 years: 1,200 mg
9–18 years: 1,500 mg

Pregnancy:(*) 1,500 mg
Lactation:(*)2,300 mg

Chloride
(Cl)

Important component of gastric juice as hydrochloric acid

Hypochloremic metabolic alkalosis. In infants, hypochloremia results in growth failure, lethargy, irritability, anorexia, gastrointestinal symptoms, and weakness; may also result in hypokalemia, metabolic alkalosis, hematuria, hyper–aldosteronism, and increased plasma renin

Dehydration, fluid loss, hyper–natremia

Adults:
19–50 years:(*) 2,300 mg
51–70 years: 2,000mg
> 70 years: 1,800 mg

Infants/children: (*)
0–6 months: 180mg
7–12months: 570mg
1–3 years: 1,500mg
4–8 years: 1,900mg
9–18 years: 2,300mg

Pregnancy: (*) 2,300mg
Lactation:(*) 2,300mg

Mineral

 Biochemical Role/Function

Deficiency Symptoms

 Toxicity Symptoms

Recommended Dietary Allowance or AI (*)

Iron

Component of enzymes necessary for oxidative metabolism; heme proteins  (hemoglobin, myoglobin, cytochromes); partici–
pates in electron transfer 

Impaired physical work performance, develop–mental delay, cognitive impairment, anemia

Fatigue, anorexia, dizziness, nausea, vomiting, headache, weight loss, shortness of breath

Adults:
Men 19+ & women 51+: 8.0 mg
Women (age 19–50): 18.0 mg

Infants/children:
0–6 months:(*) 0.27 mg
7–12 months: 11,mg
1–3 years: 7,mg
4–8 years: 10 mg
9–13 years: 8 mg
14–18 years (boys): 11 mg
14–18 years (girls): 15 mg

Pregnancy: 27 mg
Lactation:
14–18 years: 10 mg
19–50 years: 9mg

Zinc

Component of enzymes (RNA polymerase, alkaline phosphatase); structural role for some enzymes and in protein folding; anti–oxidant function as part of zinc–copper SOD  

Growth retardation, hair loss, diarrhea, delayed sexual maturation and impotence, eye and skin lesions, loss of appetite, delayed wound healing   

GI symptoms (epi–gastric pain, nausea, vomiting, abdominal cramps, diarrhea); impaired immune response; reduced copper status

Adults (ages 19+):
Men: 11.0 mg
Women: 8.0 mg

Infants/children:
0–6 months: (*) 2 mg
7 months to 3 years: 3 mg
4–8 years: 5 mg
9–13 years: 8 mg
14–18 years (boys): 11 mg
14–18 years (girls): 9 mg

Pregnancy:
14 to 18 years: 12 mg
19+ years: 11 mg

Lactation:
< 18 years: 13 mg
19+ years: 12 mg

 Copper

Component of metallo–enzymes (oxidases; eg, monoamine oxidase; lysyl oxidase used for collagen and elastin production; cytochrome c oxidase; dopamine β mono–oxygenase); part of zinc–copper SOD

Defects in connective tissue; anemia; immune and cardiac dysfunction

GI symptoms (abdominal pain, nausea, vomiting, cramps, diarrhea)

Adults (ages 19+): 900 µg

Infants/children: (*)
0–6 months:200 µg
7–12 months: 220 µg
1–3 years: 340 µg
4–8 years: 440 µg
9–13 years: 700 µg
14–18 years: 890 µg

Pregnancy: 1000 µg
Lactation: 1300 µg

Chromium

Potentiation of insulin action; mobilize the glucose transporter, GLUT4, to the plasma membrane (Mol Endocrinol. 2006;20:857–870); enhances tyrosine phosphorylation of the insulin receptor (Biochemistry.2005;44:8167–8175)

Rare; found in patients on TPN prior to inclusion of Cr+3; symptoms included weight loss, neuropathy, and impaired glucose tolerance

None for Cr+3; Cr+6 is a known carcinogen when inhaled, and oral ingestion (20 mg/l) causes GI symptoms (abdominal pain, nausea, vomiting,  diarrhea) 

Adults:
Men (age 19–50): 35 µg
Women (age 19–50): 25 µg
Males (age 50+): 30 µg
Females (age 50+): 20 µg

Infants/children: (*)
0–6 months: 0.2 µg
7–12 months: 5.5 µg
1–3 years: 11 µg
4–8 years: 15 µg
9–13 years (males): 25 µg
9–13 years (females): 21 µg
14–18 years (males): 35 µg
14–18 years (females): 24 µg

Pregnancy: 30 µg
Lactation: 45 µg

Mineral

 Biochemical role/function

  Deficiency symptoms

Toxicity  symptoms

Recommended Dietary Allowance or AI (*)

Selenium

Defense against oxidative stress, regulation of thyroid hormone action, and regulation of the redox status of vitamin C and other molecules, through
selenoproteins; eg, oxidant defense enzymes like glutathione peroxidase; iodothyronine deiodinases 

Keshan disease (cardiomyopathy in pediatric population); skeletal muscle disorders manifested by muscle pain, fatigue, proximal weakness, and serum creatine kinase (CK) elevation (Muscle Nerve.2003;27:662–668) 

Selenosis  (gastrointestinal upset, hair loss, white blotchy nails, garlic breath odor, fatigue, irritability, and mild nerve damage); hair and nail brittleness and loss
 

Adults (ages 19+): 55 µg
              
Infants/children: (*)
0–6 months: 15 µg
7–12 months: 20 µg
1–3 years: 20 µg
4–8 years: 30 µg
9–13 years: 40 µg
14–18 years: 55 µg

Pregnancy: 60 µg
Lactation: 70 µg

 Iodine

Component of the thyroid hormones thyroxine (T4) and triiodothyronine (T3)

Mental retardation, hypothyroidism, goiter, cretinism, and varying degrees of other growth and developmental abnormalities

Burning of the mouth, throat, and stomach, abdominal pain, fever, nausea, vomiting, diarrhea, weak pulse, cardiac irritability, coma, cyanosis; thyroid enlarge–ment (goiter) from increased TSH stimulation; increased risk of thyroid papillary cancer; iodermia; hyperthyroidism

Adults (ages 19+): 150 µg

Infants/children:
0–6 months:(*) 110 µg
7–12 months:(*) 130 µg
1–3 years: 90 µg
4–8 years: 90 µg
9–13 years: 120 µg
14–18 years: 150 µg

Pregnancy: 220 µg
Lactation: 290 µg

Manganese

Component of metallo–enzymes (arginase, manganese superoxide dismutase, pyruvate carboxylase)

Dermatitis, hypocholesterolemia

Neurotoxicity

Adults (ages 19+): (*)
Men: 2.3 mg
Women: 1.8 mg

Infants/children: (*)
0–6 months: 3 µg
7–12 months: 0.6 mg
1–3 years: 1.2 mg
4–8 years: 1.5 mg
9–13 years (boys): 1.9 mg
9–18 years (girls): 1.6 mg
14–18 years (boys): 2.2 mg

Pregnancy: (*) 2 mg
Lactation: (*) 2.6 mg

Molybdenum
(MO)

Component of sulfite oxidase, xanthine oxidase, aldehyde oxidase, enzymes involved in catabolism of sulfur–containing amino acids, purines, and pyridines

Rare; initially seen in patients on TPN, before addition of MO to standard TPN regimes; resulted in tachycardia, headache, night blindness, low serum uric acid 

Reproductive effects as
observed in animal studies;
with occupational exposure, hyper–uricemia, and gout symptoms   

Adults (ages 19+): 45 µg

Infants/children: (*)
0–6 months: 2 µg
7–12 months: 3 µg
1–3 years: 17 µg
4–8 years: 22 µg
9–13 years: 34 µg
14–18 years (males): 43 µg

Pregnancy/lactation: 50 µg