Vitamin D
A 40-year-old woman from Alaska presents to her physician with muscle aches and pains and generalized weakness. The following results were obtained (normal ranges in parenthesis): Calcium = 8.2 mg/dL (8.8 - 10.4) Phosphate = 2.2 mg/dL (2.3-4.7) Alkaline phosphatase = 350 U/L (30-120) PTH = 124 pg/mL (10-65) 25-hydroxy vitamin D = < 5 ng/mL (15-40) What is most likely the cause of her symptoms?
Decreased vitamin D
June is a 63-year-old female that takes a multivitamin daily that contains 400 IU of vitamin D and takes in another 50 IU from her diet. June feels she is getting enough vitamin D. Her family is concerned that she is not getting the recommended daily allowance of vitamin D from the supplement and her diet, so they are encouraging June to eat food that is higher in vitamin D to increase her daily intake. Do you agree with June or her family?
Her family is correct. June is not getting the recommended daily allowance of vitamin D from the supplement alone.
John is a 56-year-old veterinarian who was recently tested for vitamin D levels. His current result came back inconsistent with his results in the past. What could be the explanation for this erroneous results?
Heterophile antibodies are present.
A physician calls the laboratory to add on a vitamin D test to a sample drawn two days ago. The laboratory assistant pulls the sample from the refrigerator, generates a test order and label, and delivers the sample to the Chemistry department. The technologist performing the test is using a spectrophotometer-type instrument and notices the sample is grossly hemolyzed. Should the technologist continue to run the test?
No - The sample is grossly hemolyzed and this may interfere with the testing methodology.
The sample seen in the image was obtained on a patient from the ICU at 5:00 AM this morning. The following tests were ordered on the sample: Electrolytes Vitamin D (using a spectrophotometric method) Will you accept the sample to run both tests?
Reject the sample for both tests
All of the following are functions of vitamin D, EXCEPT?
Stimulates maturation of fat cells
Which of the following types of samples are NOT appropriate for vitamin D testing?
Urine, throat swab
Sarah is a 75-year-old retired school teacher originally from Minnesota. She now lives in Florida and frequents the beach four days a week. Which form of vitamin D would she most likely test the highest for?
Vitamin, D3Cholecalciferol
John's physician has told him to increase his dietary intake of vitamin D from "naturally occurring sources." What should John put on his grocery shopping list to achieve this?
all of the above
What are the potential interferences in a patient sample that, if present, may cause erroneous results in immunoassays for vitamin D?
all of the above
Rickets affects which population?
children
Vitamin D is a water soluble vitamin.
false
Joe is a new MLS in the chemistry laboratory. He is performing an immunoassay test for vitamin D. The package insert states the directions as follows: Step One: 25-hydroxy vitamin D is dissociated from its binding protein and binds to the specific solid phase antibody. Step Two: Vitamin D-isoluminol tracer is added and unbound material is removed with a wash cycle. Step Three: The reagents are added to initiate the chemiluminescent reaction. Step Four: The light signal is detected by a photomultiplier as relative light units; this measurement is inversely proportional to the concentration of 25-hydroxy vitamin D. Joe gets distracted and forgets to perform the wash cycle from step two and continues on to step three. How will this affect his results?
results will be decreased
Jane is a two-year-old girl brought to the primary health center for failure to thrive and inability to walk properly. On examination, there are skeletal deformities of both upper and lower limbs with marked bowing. General examination shows pallor, but there are no other signs. The abdomen is distended, otherwise systemic examination is normal. Based upon the above information, what is the most likely diagnosis?
rickets
The major role of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D helps the body absorb calcium, which forms and maintains strong bones.
true
