Vitamin D 25(OH)
VIT D 25 OH
Description
Vitamin D 25(OH) test measures how much 25-hydroxyvitamin D is in your blood. This helps doctors check if your vitamin D is too low, monitor the effectiveness of your supplements, or see how well your body is absorbing calcium to keep bones strong. A blood sample is taken to see if your vitamin D is normal, low, or high. Low levels are often connected to weak bones, a weakened immune system, or conditions like osteoporosis, while high levels might happen if you’re taking too much vitamin D or have other health issues. Based on the results, your doctor might recommend changes to your diet, adding supplements, or getting more sunlight. This test is particularly important for people who don’t get much sun, have darker skin, or have trouble absorbing vitamin D. Regular testing can help keep your bones strong, your immune system healthy, and your overall well-being in check.
Procedure
Invasive
Sample Type
Blood – Serum
Test Category
Vitamins
Procedure Category
Blood Draw
Units
Nanograms Per Milliliter
Test Groups
Basic Nutrient Deficiency Group: This group comprises essential tests aimed at assessing key nutrient levels vital for overall health and well-being. Cognitive Health Group: This group of tailored tests is aimed at evaluating cognitive function and assessing markers related to cognitive health, providing valuable insights for cognitive well-being and potential cognitive disorders. Complete Cardiovascular Group: This group contains comprehensive tests for an extensive evaluation of cardiovascular health, providing thorough insights into heart-related conditions beyond basic assessments. Complete Metabolic Group: A comprehensive suite of tests designed to evaluate metabolic function, offering detailed insights into various aspects of metabolism and associated health conditions. Complete Nutrient Deficiency Group: This comprehensive group includes an expanded panel of tests covering a wide range of vitamins, minerals, and other essential nutrients. Immune System Group: By evaluating various aspects of immune system function and health, this group offers insights into immune responses and related health considerations. Vitamin Group: This collection of tests encompasses a range of key vitamins crucial for physiological functions, aiding in nutritional status evaluation and deficiency detection.
Optimal Range
For All Individuals:
Conventional Unit: 50–100 ng/mL
SI Unit: 125–250 nmol/L
Normal Range
For All Individuals:
Conventional Unit: 30–100 ng/mL
SI Unit: 75–250 nmol/L
Results That Differ From The Norm (Direct and Indirect Causes)
Increased levels may indicate:
Excessive sunlight exposure
Excessive vitamin D supplementation
Over-fortification of foods with vitamin D
Primary hyperparathyroidism (Overactive parathyroid glands)
Decreased levels may indicate:
- ...
Key Reasons For Testing
Bone Health: Evaluates vitamin D’s role in calcium absorption, preventing osteoporosis and rickets.
Muscle Function: Assesses levels critical for muscle strength and fall prevention, especially in older adults.
Immune Function: Measures vitamin D’s impact on immune modulation and infection resistance.
Pregnancy Support: Ensures adequate levels for fetal skeletal development and maternal health.
Pediatric Assessment: Monitors vitamin D levels for growth and skeletal health in children.
Health Status Conditions It May Be Used To Assess
Currently, this test is not directly associated with any conditions listed on the Health Status page. However, it may be included as part of a broader set of tests linked to specific health conditions.
Some Prominent Medical Labs That May Offer This Test
Please note that this particular test has not been associated with any of the listed prominent medical labs. We recommend enquiring with your private physician or nearest hospital to determine where this specific test can be performed.
References
Important Note
Any medical procedure yielding results outside the norm may be directly or indirectly linked to the conditions outlined on this page. Various factors, including genetics, medication and supplement usage, recent illnesses, pregnancy, pre-test eating, smoking, and stress, can impact the test's outcome. Additionally, factors like false positives, false negatives, inaccurate analyses, and others can influence results.
Reference ranges, which help healthcare professionals interpret medical tests, may vary depending on age, gender, and other factors. They may also differ between laboratories due to variations in instruments and methods used. Optimal ranges are designed for preventive purposes, aiming to identify trends and potential risks early, while normal ranges reflect conventional laboratory values indicating no current disease or pathology. Your healthcare practitioner may have specific reasons for testing that deviate from the usual or may interpret results differently based on individual circumstances. Proper interpretation typically involves considering clinical findings and other diagnostic tests. Hence, it is crucial to provide your healthcare professionals with a comprehensive medical history, consult with them for result interpretation, and follow their guidance for potential re-testing or additional diagnostics.
Disclaimer
This content is provided solely for informative and educational purposes. It is not intended as a substitute for medical advice or treatment from a personal physician. Regarding the interpretation of their medical test results and/or specific health questions, it is recommended that all readers and viewers consult their physicians or other qualified health professionals. The publisher is not responsible for any adverse health effects that may result from reading or following the information in this educational content. Before beginning any nutrition, supplement, or lifestyle program, all viewers, especially those taking prescription or over-the-counter medications, should consult their physician or health care practitioner.
Please note that while prominent lab names are included in this content, we cannot guarantee that these labs offer all the tests mentioned. For confirmation, individuals should contact the labs directly or consult their medical practitioners. The information provided reflects general knowledge at the time of publication and may not include recent updates or emerging research. Readers should verify details with qualified professionals to ensure the most up-to-date and accurate guidance.
[1] Holick MF. Vitamin D Deficiency. N Engl J Med. 2007;357(3):266-281.
[2] Bikle DD. Vitamin D Metabolism, Mechanism of Action, and Clinical Applications. Chem Biol. 2014;21(3):319-329.
[3] Jones G. Pharmacokinetics of Vitamin D Toxicity. Am J Clin Nutr. 2008;88(2):582S-586S.
[4] Vieth R. Vitamin D Supplementation, 25-Hydroxyvitamin D Concentrations, and Safety. Am J Clin Nutr. 1999;69(5):842-856.
[5] Souberbielle JC, Prié D, Courbebaisse M, et al. Vitamin D and Vitamin D 25(OH): Laboratory Measurements and Clinical Utility. Front Endocrinol (Lausanne). 2018;9:329.
[6] Bouillon R, Marcocci C, Carmeliet G, et al. Skeletal and Extraskeletal Actions of Vitamin D: Current Evidence and Outstanding Questions. Endocr Rev. 2019;40(4):1109-1151.
[7] Christakos S, Dhawan P, Verstuyf A, et al. Vitamin D: Metabolism, Mechanisms of Action, and Clinical Applications. Nat Rev Endocrinol. 2016;12(4):191-202.
[8] Pettifor JM, Bikle DD, Cavaleros M, et al. Serum 25-Hydroxyvitamin D in Vitamin D Toxicity. Ann Intern Med. 1995;122(7):511-513.
[9] Pilz S, März W, Cashman KD, et al. Rationale and Plan for Vitamin D Food Fortification: A Review and Guidance Paper. Front Endocrinol (Lausanne). 2018;9:373.
[10] Wagner CL, Greer FR. Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents. Pediatrics. 2008;122(5):1142-1152.
[11] Wang TJ, Pencina MJ, Booth SL, et al. Vitamin D Deficiency and Risk of Cardiovascular Disease. Circulation. 2008;117(4):503-511.
[12] Autier P, Boniol M, Pizot C, et al. Vitamin D Status and Ill-Health: A Systematic Review. Lancet Diabetes Endocrinol. 2014;2(1):76-89.
[13] Zittermann A, Gummert JF, Börgermann J. The Role of Vitamin D in Dyslipidemia and Cardiovascular Disease. Curr Pharm Des. 2011;17(9):933-942.
[14] Pludowski P, Holick MF, Pilz S, et al. Vitamin D Effects on Musculoskeletal Health, Immunity, Autoimmunity, Cardiovascular Disease, Cancer, Fertility, Pregnancy, Dementia, and Mortality: A Review of Recent Evidence. Autoimmun Rev. 2013;12(10):976-989.
[15] DeLuca HF. Overview of General Physiologic Features and Functions of Vitamin D. Am J Clin Nutr. 2004;80(6 Suppl):1689S-1696S.