Vitamins

Usha Sethuraman

doi:10.1542/pir.27-2-44

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Usha Sethuraman, MD*

^*Division of Emergency Medicine, Carman and Ann Adams Department of Pediatrics, Children’s Hospital of Michigan, Wayne State University, Detroit, Mich

Objectives

After completing this article, readers should be able to:

Identify the symptoms and signs of deficiency of various vitamins.
Characterize the patients at risk for deficiencies and plan their treatment.
Discuss the treatment of patients at risk for vitamin deficiencies.

Introduction

Vitamins are organic compounds required in small amounts in various cellular metabolisms that are important for overall health maintenance and normal growth of the organism. First discovered by Hopkins in 1907, they were named by Funk in 1911. McCollum and Davis later showed that some vitamins, such as A, D, E, and K, are fat-soluble, and some, such as B and C, are water-soluble (Table 1).

Vitamin	Sources	Daily Requirement	Action	Deficiency	Excess	Diagnosis	Treatment
A	Green leafy vegetables, carrots, sweet potatoes, liver	<6 mo: 400 mcg 7 to 12 mo: 500 mcg 1 to 3 y: 300 mcg 4 to 8 y: 400 mcg 9 to 15 y: 600 mcg	Vision in dim light, bone and tooth growth, epithelium maturation	Nyctalopia, photophobia, keratomalacia, blindness, impaired growth, follicular hyperkeratosis	Anorexia, dry skin, painful joints, increased intracranial pressure, headache, vomiting	Clinical or low plasma retinol levels	<9 y: 600 to 900 mcg PO q day >9 y: 1,700 mcg/d PO q day until recovery
B₁ (Thiamine)	Liver, pork, milk, grains	<6 mo: 0.2 mg 6 to 12 mo: 0.3 mg 1 to 3 y: 0.5 mg 4 to 8 y: 0.6 mg 9 to 13 y: 0.9 mg >14 y: 1.2 mg	Part of thiamine pyrophosphate, which is needed for oxidative decarboxylation	Beriberi, fatigue, cardiac failure, polyneuritis	None	Response to thiamine	10 mg IV/IM/PO for 2 wk; then 5 mg q day for 1 mo
Riboflavin (B₂)	Milk, cheese, liver, green leafy vegetables	Infants: 0.3 to 0.4 mg 1 to 3 y: 0.5 mg 4 to 8 y: 0.6 mg 9 to 13 y: 0.9 mg >14 yr: 1.3 mg	Part of flavoproteins important for hydrogen transfer	Blurring of vision, cheilosis	None	Urinary riboflavin of <30 mcg/d	3 to 10 mg PO in divided doses daily
Niacin (Nicotinic acid)	Liver, fish, whole grains, eggs, milk, poultry	<1 y: 2 to 4 mg 1 to 3 y: 6 mg 4 to 8 y: 8 mg 9 to 13 y: 12 mg >13 y: 16 mg	Forms NAD and NADP cofactors	Pellagra (rash, diarrhea, stomatitis, glossitis, mental status changes)	None	Clinical and N′methylnicotinamid (NMN) excretion of <0.8 mg/d	10 to 50 mg PO q 6 h
B₁₂ (Cobalamine)	Fish, eggs, cheese	0 to 6 mo: 0.4 mcg 6 to 12 mo: 0.5 mcg 1 to 3 y: 0.9 mcg 4 to 8 y: 1.2 mcg 9 to 13 y: 1.8 mcg >13 y: 2.4 mcg	Maturation of red blood cells	Juvenile pernicious anemia	None	Megaloblastic macrocytic anemia, hypersegmented neutrophils, high lactic dehydrogenase, excessive methylmalonic acid in the urine, serum B₁₂ assays of <150 pg/mL, Schilling test	100 mcg/d IM for 2 wk; then q week until hematocrit normalizes; then 60 mcg/d IM q mo
B₆ (Pyridoxine)	Meat, liver, kidneys	<6 mo: 0.1 mg 6 to 12 mo: 0.3 mg 1 to 3 y: 0.5 mg 4 to 8 y: 6.0 mg 9 to 13 y: 1.0 mg >13 y: 1.3 mg	Decarboxylation reactions and transaminations	Seizures, irritability, sensory ataxia	Neuropathy	Whole blood concentration of pyridoxal phosphate	Seizures: 50 to 100 mg IV or IM
Folate	Cauliflower, green leafy vegetables, yeast, liver, kidney	<6 mo: 65 mcg 6 to 12 mo: 80 mcg 1 to 3 y: 150 mcg 4 to 8 y: 200 mcg 9 to 13 y: 300 mcg >13 y: 100 mcg	Maturation of red blood cells and synthesis of nucleic acids	Megaloblastic anemia, irritability, failure to gain weight		Low serum folate levels of <4 ng/mL, low red blood cell folate levels, elevated serum homocysteine levels with normal methylmalonic acid level	Infants: 15 mcg/kg per day PO/IM 1 to 13 y: I mg/d followed by 0.1 mg/d until recovery >13 y: 1 mg/d
Vitamin D	Fortified milk, liver oils, sunlight, egg yolks	<12 mo: 200 IU 1 to 15 y: 200 IU Preterm infants: 400 IU	Regulates calcium and phosphorus levels, promotes endochondral growth of long bones, mineralization of zone of provisional calcification	Rickets, tetany, bow legs, poor growth	Diarrhea, weight loss, calcification of soft tissues	Low serum calcium, phosphous, and 25 hydroxy-D₃; high alkaline phosphatase and urine cyclic AMP; widened bone ends, with cupping and fraying of long bones	Vitamin D₃ 150 to 250 mcg (5,000 to 10,000 IU) for 2 to 3 mo. After healing is complete, reduce dose to 10 mcg/d. Or a single-dose regimen of 15,000 mcg (600,000 IU) orally or parenterally
Vitamin E (Tocopherol)	Germ oils, green leafy vegetables	<6 mo: 4 mg 7 to 12 mo: 5 mg 1 to 3 y: 6 mg 4 to 6 y: 7 mg 9 to 13 y: 11 mg >14 y: 15 mg	Membrane stabilization, antioxidant	Red blood cell hemolysis, muscle weakness, double vision	Nausea, diarrhea, vitamin K antagonism	Plasma alpha-tocopherol levels <5 mg/L	15 to 25 mg/kg per day of alpha-tocopherol PO
Vitamin K	Green leafy vegetables, liver	<6 mo: 2 mcg 7 to 12 mo: 2.5 mcg 1 to 3 y: 30 mcg 4 to 7 y: 55 mcg 9 to 15 y: 60 to 75 mcg	Prothrombin formation, factors, II, VII, IX, X	Hemorrhagic manifestations	Hyperbilirubinemia, hemolytic anemia, kernicterus	Prolonged prothrombin and partial thromboplastin time, presence of des-gamma- carboxyprothrombin (DCP) in plasma	2 U first; further doses as needed
Vitamin C	Citrus fruits	<6 mo: 40 mg 7 to 12 mo: 50 mg 1 to 3 y: 15 mg 4 to 8 y: 25 mg 9 to 13 y: 45 mg >14 y: 75 mg	Integrity of intercellular material, absorption of iron and folic acid	Scurvy, poor wound healing	Oxaluria	Positive capillary fragility test, ascorbic acid levels <0.1 mg/dL or white blood cell ascorbic acid level 0 to 7 mg/dL, low levels of vitamin C in urine after a test dose of vitamin C, normal bleeding time, widening of the zone of provisional calcification on radiographs of bone ends	25 mg of ascorbic acid PO q 6 h for 1 wk

Table 1.

Vitamins: Sources, Requirements, Action, Results, Diagnosis, and Treatment

Vitamin A (Retinol)

Case 1

A 5-year-old boy who recently was adopted from India is brought by his parents for his first physical examination. They report that he has been doing well except that he seems to bump into objects frequently, particularly in the evenings. On examination, his height and weight are below the 5th percentile. He has some silver-colored patches in his conjunctiva, but the rest of the examination findings are normal. A diagnosis is made clinically and treatment initiated.

Case 2

A 3-year-old girl is brought to the emergency department for irritability. Her mother denies fever, upper respiratory tract infection symptoms, or trauma, but states that the girl has become progressively irritable over the past few days. She had been complaining of headache and nausea but had no emesis. On examination, the child is afebrile and appears irritable. Despite adequate doses of acetaminophen, she continues to complain of a headache, prompting the decision to perform a lumbar puncture. Except for an elevated opening pressure, her spinal fluid appears normal, having no white or red blood cells. Further questioning reveals that the girl has been taking her brother’s pills three to …