Vitamin deficiencies Flashcards
What is the first sign of vitamin A deficiency? What are additional signs
- First sign is dryness of eyes which feels gritty (xerophthalmia)
- Early in disease there may be no clinical signs but patients may report impaired night vision
- Bitot’s spots are grey or white plaques of damaged epithelium usually seen on the lateral aspect of the conjunctiva (can be seen at normal retinol levels)
- Worsening disease involves keratomalacia where the whole structure of the eye breaks down, leading to irreversible blindness
What foods provide vitamin A and can be attempted to increase as public health prevention of vitamin A deficiency?
- Green leafy vegetables
- Yellow and orange fruits (mango, papaya)
- Breastmilk
- Liver
- Milk
- Eggs
What is the treatment for vitamin A deficiency?
- Oral vitamin A at days 1, 2 and in week 3 as per doses in box
- Topical antibiotic eye ointment for xerophthalmia
- For corneal involvement, cover with eye pad
Who are at risk groups for vitamin B1 (thiamine deficiency)?
- Those who eat cereals/rice that are highly milled
- Alcoholism
- Nitrofurazone therapy for trypanosomiasis
What are the clinical forms of thiamine deficiency?
- Dry beriberi
- Wet beriberi
- Infantile beriberi
- Wernicke’s encephalopathy
What are clinical features/clues of dry beriberi thiamine deficiency?
Dry beriberi
* More common in SE Asia
* Diet of milled rice or may be pregnant with cultural food avoidance practices
* Gradual onset of distal limb weakness and wasting
* Sensory loss with glove and stocking distribution
* Difficulty rising from a squatting position
* Loss of proprioception and reflexes
What are clinical features/clues of wet beriberi thiamine deficiency?
Wet beriberi
* SE Asia
* Diet of milled rice
* High output cardiac failure
* Warm peripheries
* Bounding pulse
* Peripheral vasodilation
* CCF
* In acute fulminant disease, peripheries may become cool due to poor cardiac output
What are clinical clues of infantile beriberi thiamine deficiency?
Infantile beriberi
* SE Asia
* Infant breastfed by a thiamine deficient mother who may have a diet of milled rice and avoided other foods during/after pregnancy
* Occurs 2-3 months of age
* More rapid onset than congenital heart disease
* Cyanosis
* Grunting
* Oedematous extremities
What foods are rich in thiamine?
- Groundnuts
- Whole wheat
- Fruits
- Vegetables
What’s the treatment for thiamine deficiency?
- Acute beriberi - IV thiamine until symptoms improve followed by oral
- Chronic beriberi - Oral thiamine
- Infantile - IV thiamine followed by IM. Treat mother with oral thiamine
What diets are high risk for development of niacin (B3) deficiency (pellagra) and why?
- Maize - bioavailability of niacin in maize is low and is poor in tryptophan which is required for niacin synthesis
- Sorghum - high leucine levels decrease metabolism of nicotinic acid and tryptophan
When these are staples of diet there is increased risk of pellagra
What are clinical features of pellagra?
- Diarrhea
- Dermatitis (photosensitive)
- Dementia
What are risk factors for vitamin C deficiency
Diet that lacks fruit and vegetables
Nb Vitamin C easily destroyed by overcooking
What are clinical features/clues of Vitamin C deficiency?
Vitamin C deficiency
* Diet lacking fruit/vegetables or overcooking
* Gingivitis
* Bleeding gums
* Microcytic anemia due to iorn deficiency as vitamin C is required for iron absorption
What is a common cause of pyridoxine (Vitamin B6) deficiency?
- Isoniazid and pyrazinamide therapy for TB
- Supplement pyridoxine alongside these medications
What are clinical features/clues to pyridoxine (B6) deficiency?
- Isoniazid and/or pyrazinamide therapy
- Peripheral neuropathy
What are risk factors for vitamin D deficiency (rickets/osteomalacia)?
- Diet insufficiency (e.g. no fish)
- Malabsorption
- Lack of UV exposure/outdoor play
- May also occur due to lack of calcium e.g. diet of maize
What are clinical features/clues for rickets?
Rickets (disordered bone mineralization at growth plates)
* Lack of UV exposure or diet poor in vitamin D and/or calcium
* Usually <2 years of age
* Tender and bowed legs if age of standing
* Painful wrists
* Swollen costo-chondral junctions (rickety rosary)
* Neurodevelopmental delay
How is rickets diagnosed?
- Mostly clinical
X-rays
* Cupping and fraying of metaphyses and widened epiphyses
* Partial fractures without bony displacement of femur, pelvis, scapular border
What food is high in vitamin K?
Green leafy vegetables
What are clinical features/clues to vitamin K deficiency?
- Lack of green leafy vegetables in diet
- Poorly fed neonate
- Adults with malabsorption
- Increased bleeding tendency
- Increased prothrombin time
Which clotting factors require vitamin K?
- 2, 7, 9, 10
- Protein C, Protein S
What are risk factors for iodine deficiency
- Usually due to low levels in soil and water
- Mountainous areas (Nepal, Bolivia)
- Post-flooding with iodine washed out from soil (e.g. Bangladesh)
- Worsened by eating brassicas, cassava, soya beans
What are clinical features of iodine deficiency?
Iodine deficiency
* Goitre
* Hypothyroidism (most commonly are euthyroid)
* Mental retardation
* Speech and hearing deficits
* Apathetic facies
What are risk factors for zinc deficiency?
- Minimal body stores and deficiency can occur quickly
- Diet poor in meat and fish
- Severe malnutrition/catabolic states
- Low birth weight infants
What are clinical features/clues for zinc deficiency?
Zinc deficiency
* Experiencing malnutrition
* Low birth weight infant
* Failure to thrive
* Recurrent infections
* Persistent diarrhea
* Scaly lesions on feet and buttocks
* Developmental delay
