Thiamine Deficiency-Vitamin B1
- Beriberi- “I can’t, I can’t” in Singhalese-Dutch East Indies, now Sri Lanka
- 1st nutritional disorder recognized-17 century, although thiamine etiology recognized in 20th century
- Presently rare in developed countries-due to restrictive diet, alcoholism, weight reduction surgery, recurrent vomiting
- B1 is water soluble vitamin-present in most plant/animal tissue-greatest source is cereal grains, wheat germ, yeast, soybean flour, pork.
- Recommended daily allowance-1-1.5 mg daily-no toxicity from over ingestion.
- Deficiency symptoms-develop gradually over weeks to months, but on occasion rapidly.
- Fatigue, irritability, muscle cramps
- Prolonged deficiency- burning dysesthesia toes/feet and/or mild sensory loss
- Pain may be predominate feature.
Vitamin B6 Deficiency- Pyridoxine
- Neuropathy from both deficiency and toxicity
- Commonly seen due to side effect from TB and HTN meds
- Also seen in malnutrition from alcoholism or pts receiving chronic peritoneal dialysis.
- Peripheral neuropathy- axonal sensorimotor type
- Striking clinical symptom of ataxic sensory neuropathy-numbness/tingling with ataxic gait
- May occur in doses as low as 200 mg per day. Daily intake greater than 100 mg is probably best avoided
Vitamin B12 Deficiency- Cobalamin deficiency
- Pernicious anemia and other conditions of malabsorption are the most common cause
- Pathology occurs in the posterior columns and lateral spinal cord tract, producing vibratory and position sense deficit, along with paraparesis and plantar responses.
- Peripheral nerve pathology without in absence of myelopathy controversial.
- Rarely due to inadequate dietary intake.
- B12 only present in animal products
- Vegans need to ingest some form as supplement; vegetarians can consume egg or dairy products
Vitamin E Deficiency
- Present in animal fat, vegetable oils, and various grains-deficiency usually due to factors other than insufficient intake
- Deficiency usually due to lipid malabsorption.
- Pathology-swelling and degeneration of axons in the posterior column (vibratory/position sense deficit) and Spinocerebellar tracts-resembles Friedreich’s ataxia. May present as isolated peripheral neuropathy-but this is rare.
- NCS-sensory neuropathy.
- Treatment with high doses vitamin E
- Mostly underdeveloped countries where corn is main source of carbohydrate
- Most Western countries have niacin enriched bread.
- peripheral neuropathy mild, resembles beriberi; axonal degeneration
- Treatment with niacin supplement-40-250 mg per day may not resolve neuropathy.
- Peripheral neuropathy may follow gastric surgery for ulcer, cancer, or weight reduction.
- peripheral neuropathy-non specific axonal sensory/motor loss
- Usually occurs in the context of rapid, significant weight loss and recurrent protracted vomiting.
- Treatment-vitamin supplement to include niacin