Table 2:
Vitamin Functions, Deficiency Diseases,Toxicity Symptoms,
and Dietary Reference Intakes*

Vitamin

Functions/Roles
in metabolism

Deficiency Symptoms

Toxicity Symptoms

Recommended Dietary Allowance

Vitamin A

Bone growth, reproduction, cell division, immunity, cell differentiation

Clinical: Night blindness; total blindness (rare in the U.S.)
Subclinical: May increase risk for respiratory and diarrheal infections; decrease growth rate; slow bone develop–ment; and decrease likelihood of survival from serious illness 

Birth defects, liver abnormalities, reduced bone mineral density;     central nervous system disorders (eg, pseudotumor cerebri)

Adults: Age 19+:
Males: 900 μg
Females: 700 μg

Infants/children: (*)
0–6 months: 400 μg
7–12 months: 500 μg
1–3 years: 300 μg
4–8 years: 400 μg
9–13 years: 600 μg
14–18 years (boys): 900 μg
14–18 years (girls): 700 μg

Pregnancy:
Age < 18: 750 μg
Age 19+ 770 μg
Lactation:
Age < 18: 1,200 μg
Age 19+: 1,300 μg

Vitamin D

Maintenance of normal blood levels of calcium and phos–phorus; promotes bone mineralization; regulates cell growth, differentiation,  immune function

In children: rickets
In adults: osteomalacia

Nausea, vomiting, poor appetite, constipation, weakness, and weight loss; mental status changes; hypercalcemia; calcinosis

Adults:(*)
Ages19–50: 5 μg/200 IU
Ages 51–70: 10 μg/400 IU
Ages 70+: 15 mg/ 600 IU

Infants /children: (*)  
1–18 years: 5 μg/200 IU
 
Pregnancy/ lactation: (*) 5 μg/200 IU

Vitamin E

Antioxidant (protects cells against free radicals); plays role in immune function and in DNA repair; inhibits cell proliferation, platelet aggregation, and monocyte adhesion1

Nerve degeneration in hands and feet

Can influence coagulation in some persons with drug–induced vitamin K deficiency; anti–platelet effect

Adults:19+ years: 15mg

Infants/children: (*)
0–6 months: 4mg
7–12 months: 5mg
1–3 years: 6mg
4–8 years: 7mg
9–13 years: 11mg
14–18 years: 15mg

Pregnancy: 15mg
Lactation: 19mg

Vitamin K

Coenzyme for synthesis of proteins involved in blood coagulation and bone metabolism

Increase in prothrombin time; in severe cases,  hemorrhagic events

None currently known

Adults: 19+ years: (*)
Males: 120 μg
Females: 90 μg

Infants/children: (*)
0–6 months: 2 μg
7–12 months: 2.5 μg
1–3 years: 30 μg
4–8 years: 55 μg
9–13 years: 60  μg
14–18 years (boys):    120 μg
14–18 years (girls): 75 μg

Pregnancy/lactation:
Girls < 18 years: 75 μ g
Adults 19 + years: 90 µg

Vitamin

Functions
/Roles in Metabolism

Deficiency Symptoms

Toxicity Symptoms

Recommended Dietary
Allowance

 Vitamin C

Antioxidant; biosynthesis of connective tissue components (collagen, elastin, fibronectin, proteoglycans, bone matrix, and elastin–associated fibrillin); carnitine, and neuro–transmitters

Scurvy (involves deterioration of elastic tissue); follicular hyperkeratosis, petechiae, ecchymoses, coiled hairs, inflamed and bleeding gums, perifollicular hemorrhages, joint effusions, arthralgia, and impaired wound healing; dyspnea, edema, Sjögren syndrome, weakness, fatigue, depression

Nausea, abdominal cramps, and diarrhea (from supplements)

Adults (> 19 years):
Males: 90mg
Females: 75mg

Infants/children: (*)
0–6 months: 40mg
7–12 months: 50mg
1–3 years: 15mg
4–8 years: 25mg
9–13 years: 45mg
14–18 years (boys): 75mg
14–18 years (girls): 65mg

Pregnancy:
Age < 18: 80mg
Age 19–50: 85mg

Lactation:
Age < 18: 115mg
Age 19+: 120mg

Thiamine
(B1)

Coenzyme in the metabolism of carbohydrates and branched–chain amino acids

Anorexia; weight loss; mental changes such as apathy, decrease in short–term memory, confusion, and irritability; muscle weakness; cardiomegaly; beriberi (polyneuritis)

Oral forms: None currently known

Parenteral: Pruritus (rare: 1% of patients); extremely rare anaphylactic reaction

IOM conclusion: Even  high–dose IV use is relatively safe

Adults (> 19 years):
Males: 1.2mg
Females: 1.1mg

Infants/children: (*)
0–6 months: 0.2mg
7–12 months: 0.3mg
1–3 years: 0.5mg
4–8 years: 0.6mg
9–13 years: 0.9mg
14–18 years (boys): 1.2 mg
14–18 years (girls): 1.1 mg

Pregnancy/lactation: 1.4 mg

Riboflavin (B2)

Coenzyme in numerous redox reactions

Ariboflavinosis; sore throat; hyperemia and edema of pharyngeal and oral mucous membranes; cheilosis; angular stomatitis; glossitis (magenta tongue); seborrheic dermatitis; normochromic, normocytic anemia

 None currently known

Adults (ages 19+):
Males: 1.3mg
Females: 1.1mg

Infants/children: (*)
0–6 months: 0.3mg
7–12 months: 0.4mg
1–3 years: 0.5mg
4–8 years: 0.6mg
9–13 years (boys): 0.9mg
14–18 years (boys): 1.3mg
9–13 years (girls): 0.9mg
14–18 years (girls): 1.0mg

Pregnancy: 1.4mg
Lactation: 1.6mg

Niacin (B3)

Coenzyme in numerous redox reactions

Pellagra (pigmented rash, vomiting, constipation or diarrhea, bright red tongue; neurological symptoms including depression, apathy, headache, fatigue, and loss of memory)

From nicotinamide: nausea, vomiting, and signs and symptoms of liver toxicity (at intakes of 3,000 mg/day); from nicotinic acid: same signs at 1,500 mg/day (most toxicity related to pharmacologic use); hepatotoxicity (at doses of 3–9 g/day); blurred vision, toxic amblyopia, macular edema (doses of 1.5–5g/day) 

Adult males and males >age 14: 16mg
Adult females and females >age 14: 14mg

Infants/children: (*)
0–6 months: 2.0mg
7–12 months: 4.0mg
1–3 years: 6.0mg
4–8 years: 8.0mg
9–13 years (boys): 12.0mg

Pregnancy: 18mg
Lactation: 17mg

Panto–
thenic acid (B5)

Component of coenzyme A; cofactor and acyl group carrier for many enzymatic processes, and acyl carrier protein, a component of the fatty acid synthase complex

Extremely rare; irritability and restlessness; fatigue; apathy; malaise; sleep disturbances; gastro–intestinal complaints such as nausea, vomiting, and abdominal cramps; neurobiological symptoms such as numbness, paresthesias, muscle cramps, staggering gait

None currently known

Adults (ages 19+): 5.0mg

Infants/children: (*)
0–6 months: 1.7mg
7–12 months: 1.8mg
1–3 years: 2.0mg
4–8 years: 3.0mg
9–13 years (boys): 4.0mg
14–18 years (boys): 5.0mg

Pregnancy: 6.0mg
Lactation: 7.0mg

Pyridoxine (B6)

Coenzyme in the metabolism of amino acids, glycogen, and sphingoid bases

Seborrheic dermatitis, microcytic anemia, epileptiform convulsions

Sensory neuropathy with high (>100 mg) supplementary intake

Adults:
Ages 19–50: 1.3mg
Age 51+ (males): 1.7mg
Age 51+ (females): 1.5mg

Infants/children: (*)
0–6 months: 0.1mg
7–12months: 0.3mg
1–3 years: 0.5mg
4–8 years: 0.6mg
9–13 (boys/girls): 1.0mg
14–18 years (boys): 1.3mg
14–18 years (girls): 1.2mg

Pregnancy: 1.9mg
Lactation: 2.0mg

 Folic acid

Coenzymes are involved in DNA synthesis; amino acid interconversions; single–carbon metabolism; methylation reactions

Early sign: hypersegmented  neutrophils
Late sign:
macrocytic anemia (weakness, fatigue, difficulty concentrating, irritability, headache, palpitations, shortness of breath)

None in healthy individuals; may decrease phenytoin levels and trigger seizures in patients with seizure disorder (Neurology. 2005;64:1982); may precipitate or exacer–bate neuropathy in vitamin B12–deficient individuals 

Adults (ages 19+): 400 µg

Infants/children: (*)
0–6 months: 65 µg
7–12months: 80 µg
1–3 years: 150 µg
4–8 years: 200 µg
9–13 years: 300 µg
14–18 years: 400 µg

Pregnancy: 600 µg
Lactation: 500 µg

Vitamin B12

Cofactor for methionine synthase and L–methyl–malonyl–CoA mutase; essential for normal blood formation and neurologic function

Pernicious anemia; neuro–logic manifestations (sensory disturbances in the extremities; motor disturbances, including abnormalities of gait); cognitive changes (loss of concentration; memory loss, disorientation and frank dementia); visual disturbances, insomnia, impotency, and impaired bowel and bladder control

None currently known

Adults (ages 19+): 2.4 µg

Infants/children: (*)
0–6 months: 0.4 µg
7–12months: 0.5 µg
1–3 years: 0.9 µg
4–8 years: 1.2 µg
9–13 years: 1.8 µg
4–18 years: 2.4 µg

Pregnancy: 2.6 µg
Lactation: 2.8 µg

 Biotin

Coenzyme in bicarbonate–dependent carboxylation reactions (eg, acetyl–CoA carboxylase, pyruvate carboxylase)

Dermatitis, conjunctivitis, alopecia, and central nervous system abnormalities (depression, lethargy, hallucinations, and paresthesia of the extremities)

None currently known

Adults (ages 19+) (*): 30 µg

Infants/children: (*)
0–6 months: g
7–12 months: 6 µg
1–3 years: 8 µg
4–8 years: 12 µg
9–13 years: 20 µg
14–18 years: 25 µg

Pregnancy: 30 µg
Lactation: 35 µg

Choline

Synthesis and release of acetylcholine; precursor for the synthesis of cell membrane components  (phospholipids and sphingomyelin), platelet activating factor, and betaine (important in metabolism of homocysteine)

 Steatosis, liver damage

Fishy body odor, sweating, salivation, hypotension, mild hepatotoxicity

Men (ages 19+): 550mg
Women (ages 19+): 425mg

Infants/children: (*)
0–6 months: 125mg
7–12months: 150mg
1–3 years: 200mg
4–8 years: 250mg
9–13 (boys/girls): 375mg
14–18 years (boys): 550mg
14–18 years (girls): 400mg

Pregnancy: 450 mg
Lactation:550 mg