Beriberi (Thiamine Deficiency)

Beriberi results from a deficiency in thiamine (vitamin B₁), a coenzyme essential for carbohydrate metabolism that promotes growth and maintains muscle tone and heart function. Beriberi occurs primarily in rice-eating countries, such as China, where the main staple is polished rice from which the vitamin-containing skin and germ have been removed. Infantile beriberi is common in breast-fed infants 2 to 4 months of age whose mothers have thiamine deficiency. Noninflammatory degeneration of the myelin sheath caused by thiamine deficiency produces a peripheral neuropathy characterized by weakness of the limbs and a “pins and needles” sensation in the extremities.

Pellagra (Niacin Deficiency)

Pellagra, caused by a deficiency of niacin viamin B₃), is characterized by reddening and scaling of the skin on exposed parts of the body, vomiting and severe diarrhea, and nervous and mental disorders (ranging from chronic depression to violent, irrational behavior). The body requires niacin to complete the cellular process called respiration, in which nutrients and oxygen reach the cells through a series of chemical reactions. As a result of dietary supplements, epidemics of pellagra no longer exist; however, sporadic incidences occur among chronic alcoholics and people suffering from malabsorption.

Scurvy (Vitamin C Deficiency)

In patients with scurvy, the deficiency of ascorbic acid vitamin C) leads to an inability of the supporting tissues to produce and maintain vascular endothelium and the cementing substances that hold epithelial cells together (collagen, osteoid, dentin). Scurvy was classically a disease of sailors and explorers deprived of fresh fruit and vegetables containing vitamin C.

Weakening of capillary walls in scurvy often results in bleeding into the skin, joints, and internal organs. The gums are especially affected and bleed easily. The open lesions provide an entry for bacteria, leading to necrosis of gum tissue and tooth loosening and loss. Impaired synthesis of collagen leads to poor and delayed wound healing.

Rickets (Vitamin D Deficiency)

Rickets is a bone disease of young children in which a lack of vitamin D leads to decreased absorption of calcium from the gastrointestinal tract, resulting in weak, deformed bones. In adults, lack of vitamin D causes generalized softening of bones (osteomalacia). The radiographic findings of rickets and osteomalacia are found in Chapter 4.

Vitamin A Deficiency

Vitamin A, or retinol, is essential for vision because it is a vital component of the pigment that absorbs light in the rods of the retina. A lack of vitamin A results in night blindness, an inability to see in dim light. Vitamin A also is important for maintaining the integrity of the mucous membranes lining the respiratory, gastrointestinal, and urogenital tracts. A lack of vitamin A makes these membranes dry and susceptible to cracking, permitting infectious organisms to enter the underlying tissues.

Vitamin A is derived from β-carotene, a yellow plant pigment that is converted into vitamin A by the liver. Good sources of vitamin A include dairy products, egg yolks, fish, and vegetables such as carrots, spinach, and sweet potatoes.

Vitamin K Deficiency

Vitamin K, a fat-soluble vitamin, is necessary for the formation of prothrombin, an essential ingredient in the blood-clotting mechanism. It is primarily found in green leafy vegetables. A deficiency of vitamin K results in excessive bleeding.

Treatment of Vitamin Deficiencies

Any of the following three approaches can be used to treat vitamin deficiencies: (1) the patient’s diet is modified to include foods that contain the recommended daily requirements, (2) the patient is given synthetic oral supplements, and (3) vitamins are injected. Some deficiencies may be associated with absorption abnormalities resulting from a lack of the specific vitamins needed to absorb and process vitamins.

Dietary modifications for vitamin B deficiencies include increasing the intake of protein (meat), green leafy vegetables, and milk. For vitamin C deficiencies, an increase in consumption of fresh fruits and green leafy vegetables may help. Vitamin D deficiencies require the addition of cod liver oil, egg yolks, butter, and oily fish to the diet. Fortified milk and exposure to sunlight also provide vitamin D. To increase vitamin A, a diet including more liver, meat, eggs, milk, and dark green and yellow vegetables is of value. Eating more spinach, lettuce, broccoli, Brussels sprouts, and cabbage increases dietary vitamin K.

Radiographic Appearance

Excess vitamin D causes too much calcium to be absorbed from the gastrointestinal tract. The resulting hypercalcemia leads to the deposition of calcium in the kidney, heart, lungs, and wall of the stomach (Figure 12-3).

Treatment

Because there is an excess of vitamins, treatment requires a decrease in vitamin intake and monitoring of the patient to ensure that the levels are stable.

Radiographic Appearance

Retarded bone growth with thinned cortices usually occurs in protein-calorie malnutrition. Atrophy of the thymus gland and lymphoid tissues diminishes the child’s resistance to infection from organisms that enter the body through skin lesions and the damaged mucous membranes of the gastrointestinal tract. Mental development is also impaired, and brain atrophy can be demonstrated radiographically.