NIH Clinical Center
Dept. of Lab Medicine | Dept. of Transfusion Medicine | Anatomic Pathology Test Guide
  
 
Test Name:Vitamin D 25-Hydroxy
Protocol Use Only:
Department:Laboratory Medicine
Lab Area:Chemistry
Last Modified on:02/03/2014 01:41:58 PM
Synonyms:25-OH Vit. D, 25OH
 
Reference Ranges:

Vitamin D 25-Hydroxy  ng/mL  (SI: nmol/L = 2.496 x ng/mL)
Performed at National Institutes of Health, Bethesda MD
Effective 29Jan14 – present:
Total Vitamin D 25-OH
<10 ng/mL (severe deficiency)
Could be associated with osteomalacia or rickets

10-32 ng/mL (mild to moderate deficiency)
May be associated with increased risk of osteoporosis
or secondary hyperparathyroidism

33-100 ng/mL (optimum levels)
Optimum levels in the normal population

>100 ng/mL (toxicity possible)
100 ng/mL is the lowest reported level associated with toxicity in patients without primary hyperparathyroidism who have normal renal function. Most patients with toxicity have levels >150 ng/mL. Patients with renal failure can have very high 25-OH-VitD levels without any signs of toxicity, as renal conversion to the active hormone 1,25-OH-VitD is impaired or absent.

These reference ranges represent clinical decision values that
apply to males and females of all ages, rather than population-
based reference values. Population reference ranges for
25-OH-VitD vary widely depending on ethnic background, age,
geographic location of the studied populations, and the
sampling-season. Population-based ranges correlate poorly with serum 25-OH-VitD concentrations that are associated with biologically and clinically relevant vitamin D effects and are therefore of limited clinical value.

Effective 03Oct - 28Jan14:
Total Vitamin D 25-OH, D2+D3

<10 ng/mL    (severe deficiency)
              Could be associated with osteomalacia or rickets
10-32 ng/mL  (mild to moderate deficiency)
              May be associated with increased risk of osteoporosis
              or secondary hyperparathyroidism
33-100 ng/mL (optimum levels)
              Optimum levels in the normal population
>100 ng/mL   (toxicity possible)
              100 ng/mL is the lowest reported level associated with
              toxicity in patients without primary hyperparathyroidism
              who have normal renal function. Most patients with
              toxicity have levels >150 ng/mL. Patients with renal failure
              can have very high 25-OH-VitD levels without any signs
              of toxicity, as renal conversion to the active hormone
              1,25-OH-VitD is impaired or absent.
These reference ranges represent clinical decision values that
apply to males and females of all ages, rather than population-
based reference values. Population reference ranges for
25-OH-VitD vary widely depending on ethnic background, age,
geographic location of the studied populations, and the
sampling-season. Population-based ranges correlate poorly with serum 25-OH-VitD concentrations that are associated with biologically and clinically relevant vitamin D effects and are therefore of limited clinical value.
Effective 10Dec09 – 02Oct12:
Total Vitamin D 25-OH, D2+D3
<10 ng/mL (severe deficiency)
                 Could be associated with osteomalacia or rickets
10-24 ng/mL (mild to moderate deficiency)
                    May be associated with increased risk of osteoporosis
                    or secondary hyperparathyroidism
25-80 ng/mL (optimum levels)
                    Optimum levels in the normal population
>80 ng/mL (toxicity possible)
                  80 ng/mL is the lowest reported level associated with
                  toxicity in patients without primary hyperparathyroidism
                  who have normal renal function. Most patients with
                  toxicity have levels >150 ng/mL. Patients with renal failure
                  can have very high 25-OH-VitD levels without any signs
                  of toxicity, as renal conversion to the active hormone
                  1,25-OH-VitD is impaired or absent.
These reference ranges represent clinical decision values that
apply to males and females of all ages, rather than population-
based reference values. Population reference ranges for
25-OH-VitD vary widely depending on ethnic background, age,
geographic location of the studied populations, and the
sampling-season. Population-based ranges correlate poorly with
serum 25-OH-VitD concentrations that are associated with biologically
and clinically relevant vitamin D effects and are therefore of limited
clinical value.

Effective 12Dec01 – 09Dec09:
>=16yrs               10 – 68

Performed at Mayo Medical Labs, Rochester MN
Effective 20Mar00 – 11Dec01:
>=16yrs                 8 – 38  

Effective 19Sep94 – 19Mar00:
Winter (D2+D3)    14 – 42
Summer (D2+D3) 15 – 80

Effective 19Sep94 – 11Dec01:
Normal values were determined in the wintertime in Rochester, MN. Normal patients who have increased exposure to sunlight may have values above this normal range.

Performed at SmithKline Beecham, Van Nuys CA
Effective 14Dec83 – 18Sep94:   10 – 55

 
 
 

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