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49 Cards in this Set
- Front
- Back
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What is the suggested daily intake of vitamin D for healthy adults?
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200 international units (IU)
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What is the suggested daily intake of vitamin D for children, pregnant women, and lactating mothers?
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400 IU
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What is the only natural dietary source of vitamin D?
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Oily fish
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What is the serum calcium level with vitamin D deficiency?
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Decreased (due to decreased absorption)
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What is the resulting effect on PTH?
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Increased (in response to low calcium)
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What two clinical features of nutritional rickets are most sensitive and specific?
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Wrist enlargement
Costochondral enlargement |
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What is the serum phosphate level?
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Decreased (due to high PTH)
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What does treatment of vitamin D deficiency rickets consist of?
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5000 IU per day of vitamin D
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Deficient calcium intake has what effect on PTH levels?
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PTH levels become elevated
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What effect does this have on vitamin D levels?
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Increases vitamin D levels (attempt to absorb greater amounts of calcium, phosphate)
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What are serum phosphate levels?
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May actually be low (due to elevated PTH)
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What is the treatment of calcium deficiency rickets?
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750 mg/day of calcium
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Deficient phosphate intake has what effect on PTH levels?
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None (PTH responds only to high phosphate)
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What effect does low serum phosphate have on vitamin D levels?
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Increases vitamin D levels (attempt to absorb greater amounts of phosphate)
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What is the treatment of phosphate deficiency rickets?
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Oral phosphate supplementation
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Inheritance?
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Autosomal recessive (AR)
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Mutation?
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Defect in renal 1,25-hydroxylase
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What is the effect of defective hydroxylase?
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No conversion of inactive vitamin D to active form
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What is the characteristic clinical feature?
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Rachitic rosary responsive to vitamin D
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What is the resulting serum calcium level?
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Decreased
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What is the resulting serum phosphate level?
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Decreased (due to decreased absorption)
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What is the resulting serum PTI-I level?
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Elevated (in response to low calcium)
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What is the treatment of vitamin D-dependent rickets (VDDR) type I?
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Oral activated vitamin D
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Defect?
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No receptor for 1,25-vitamin D at target cells
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What is the serum level of 1,25-vitamin D?
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Very high
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What is the serum level of active vitamin D in type I?
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Very low in type
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What are the two characteristic clinical features?
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Alopecia
Rachitic rosary unresponsive to vitamin D therapy |
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What is the treatment of VDDR type II?
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Vitamin D analogue
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What is the relative severity of both types of vitamin D dependent rickets are more severe vs. nutritional rickets?
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Vitamin D dependent rickets I and ll
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What is the relative frequency of hypophosphatemic rickets as a cause States of rickets?
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Most common cause in the United
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What is the inheritance?
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XLD
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What is the mutation?
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Impaired renal tubular absorption of phosphate
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What is the gene?
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PHEX
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This disorder is also known as what?
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Vitamin D resistant rickets
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What is the serum phosphate level?
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Low, because a lot of phosphate is lost in the urine
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What is the resulting PTH level?
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Normal (no PTH response to low serum phosphate)
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What is the serum calcium level?
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Normal
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What is the classic triad of clinical features?
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Short child
Lower limb deformities Low serum phosphate |
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What are the two components of treatment of hypophosphatemic
rickets? |
High-dose phosphate replacement
High-dose vitamin D (to facilitate phosphate absorption) |
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What is the inheritance?
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AR
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What is the defect?
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Enzymatic deficiency leads to low levels of alkaline phosphate
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Clinical features are similar to what group of disorders?
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Nutritional rickets
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How is hypophosphatasia diagnosed?
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Elevated urinary . phosphoethanolamine
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What is the treatment of hypophosphatasia?
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No good options exist
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High-turnover renal osteodystrophy displays clinical features similar to what other disorder?
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Primary hyperparathyroidism (for example, osteitis Hbrosa cystica)
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The renal osteodystrophy spine has what appearance?
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Rugger jersey spine
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This spine appearance is also associated with what other disorder?
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Osteopetrosis
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Hypophosphatasia displays clinical features similar to what other disorder?
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Nutritional rickets
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The spine has what appearance in hypophosphatasia?
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Rachitic rosary (like rickets)
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