TY - JOUR
T1 - Clinical utility of serum folate measurement in tertiary care patients
T2 - Argument for revising reference range for serum folate from 3.0ng/mL to 13.0ng/mL
AU - Singh, Gurmukh
AU - Hamdan, Hana
AU - Singh, Vivek
N1 - Funding Information:
The authors are grateful to Mr. Vu Pham, Ms. Joyce Oliver, Ms. Lynn Tesch, and Ms. Valerie Payne for technical assistance in record retrieval. Research support from HooperHolmes International Inc. if gratefully acknowledged.
PY - 2015
Y1 - 2015
N2 - Objective: Assess the need for folate testing, frequency of corrective action, and determine reference level for serum folate. Methods: Serum folate levels in 5313 samples from 4448 patients, and clinical data were reviewed for patient characteristics and for (a) evidence of corrective action in patients with serum folate values <5.5 ng/mL, and (b) differences in patients with serum folate levels <5.5 ng/mL and patients with levels >25.7 ng/mL. Results: The prevalence of serum folate levels, in patients, <3.0, <4.0, <5.5, <7.0 and <13.0 ng/mL was 0.58%, 1.55%, 4.9%, 9.98% and 43.21% respectively. Patients with serum folate levels <5.5 ng/mL had lower serum albumin and hemoglobin. In 64% of patients with serum folate >25.7 ng/mL the sample was collected after supplementation with folic acid. Of the 128 patients with serum folate <5.5 ng/mL documentation of supplementation was present in only 38.9%. Conclusions: Serum folate levels are below the current "normal" level of 3.0 ng/mL in a larger proportion of tertiary care patients than that reported for ambulatory patients. In patients with folate deficiency, corrective action is lacking in >60% of the patients. Since serum folate levels ≥13.0 ng/mL are needed for optimal prevention of neural tube defects in the embryo/fetus, we propose that normal serum folate level should be designated to be ≥ 13.0 ng/mL.
AB - Objective: Assess the need for folate testing, frequency of corrective action, and determine reference level for serum folate. Methods: Serum folate levels in 5313 samples from 4448 patients, and clinical data were reviewed for patient characteristics and for (a) evidence of corrective action in patients with serum folate values <5.5 ng/mL, and (b) differences in patients with serum folate levels <5.5 ng/mL and patients with levels >25.7 ng/mL. Results: The prevalence of serum folate levels, in patients, <3.0, <4.0, <5.5, <7.0 and <13.0 ng/mL was 0.58%, 1.55%, 4.9%, 9.98% and 43.21% respectively. Patients with serum folate levels <5.5 ng/mL had lower serum albumin and hemoglobin. In 64% of patients with serum folate >25.7 ng/mL the sample was collected after supplementation with folic acid. Of the 128 patients with serum folate <5.5 ng/mL documentation of supplementation was present in only 38.9%. Conclusions: Serum folate levels are below the current "normal" level of 3.0 ng/mL in a larger proportion of tertiary care patients than that reported for ambulatory patients. In patients with folate deficiency, corrective action is lacking in >60% of the patients. Since serum folate levels ≥13.0 ng/mL are needed for optimal prevention of neural tube defects in the embryo/fetus, we propose that normal serum folate level should be designated to be ≥ 13.0 ng/mL.
KW - Neural tube defects
KW - Optimum serum folate level
KW - Prevalence of folate deficiency
KW - Serum folate
KW - Utility of folate testing
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U2 - 10.1016/j.plabm.2015.03.005
DO - 10.1016/j.plabm.2015.03.005
M3 - Article
AN - SCOPUS:84938679827
VL - 1
SP - 35
EP - 41
JO - Practical Laboratory Medicine
JF - Practical Laboratory Medicine
SN - 2352-5517
IS - 1
ER -