Vitamin D deficiency

Last updated: November 20, 2023

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Summarytoggle arrow icon

Vitamin D deficiency is characterized by low serum vitamin D levels, although there is significant debate among professional societies over what level constitutes a deficiency. Causes include decreased cutaneous production of vitamin D, insufficient dietary intake, inadequate gastrointestinal absorption, impaired vitamin D metabolism (i.e., decreased activation, increased deactivation), and excessive losses. Patients are typically asymptomatic unless the deficiency is severe, in which case symptoms of complications (e.g., rickets, osteomalacia, hypocalcemia) may develop. Screening for vitamin D deficiency should be performed in individuals with conditions placing them at increased risk (e.g., those causing impaired metabolism or absorption of vitamin D), and may be considered in certain population groups (e.g., individuals with obesity, who are pregnant and/or lactating, or who have darker skin pigmentation). 25-hydroxyvitamin D (25-OHD) is the best diagnostic marker for vitamin D deficiency. Additional diagnostic studies are performed if complications or underlying conditions are suspected. Management involves the administration of vitamin D in addition to treatment of any associated complications and/or underlying conditions. Ensuring adequate daily vitamin D intake, especially in patients at increased risk for vitamin D deficiency, can help prevent associated complications.

Etiologytoggle arrow icon

Causes of impaired vitamin D synthesis [2][3][4]

Inadequate cutaneous synthesis of vitamin D3

  • Inadequate exposure to UV radiation, e.g., due to:
    • Living in sufficiently northern or southern latitudes (typically above or below 33 degrees)
    • Residence in an institution
    • Sunscreen use
    • Skin covering for cultural or religious reasons
  • Darker skin pigmentation [5]
  • Older age [3]

The most common cause of vitamin D deficiency is inadequate exposure to UV radiation. [2]

Inadequate dietary intake

Causes of impaired metabolism of vitamin D

Causes of impaired absorption of vitamin D [2][12]

Malabsorptive conditions can cause multiple dietary deficiencies, especially in fat-soluble vitamins (A, D, E, and K). These include:

Other causes [2]

Clinical featurestoggle arrow icon

Screeningtoggle arrow icon

Diagnosticstoggle arrow icon


Do not routinely test for vitamin D deficiency in patients presenting exclusively with other conditions, e.g., osteoarthritis, chronic pain, fatigue, and/or depression. [16]

Interpretation of serum 25-OHD levels [4][8][20]

Classification of vitamin D status [2][3][18][21]
Vitamin D status IOM [3] Endocrine Society [2]
  • < 12 ng/mL
  • < 20 ng/mL
  • 12–19 ng/mL (potentially) [3]
  • 20–29 ng/mL
  • ≥ 20 ng/mL
  • ≥ 30 ng/mL

Do not use 1,25(OH)2D levels to diagnose Vitamin D deficiency. 1,25(OH)2D is often normal or elevated in vitamin D deficiency as a result of elevated PTH levels. [12][22]

A serum 25-OHD level of < 20 ng/mL usually requires treatment; some patients may benefit from treatment at < 30 ng/mL. [2][3]

Additional studies [4][11][12]

Imaging is not routinely performed during the workup for vitamin D deficiency. If it is performed, it may show radiographic features of osteomalacia and/or rickets (e.g., Looser zones).

In the initial stages of vitamin D deficiency, serum levels of PTH, ALP, phosphorus, and calcium may be within normal range. [12]

Treatmenttoggle arrow icon

Initial management [2]

Individuals with obesity or malabsorption syndromes, or who take medications that affect vitamin D metabolism, typically need higher doses of vitamin D and calcium (e.g., 2–3 times the normal treatment doses). [2][8]

Monitoring and follow-up [2]

Patients with extrarenal production of 1,25(OH)2D or primary hyperparathyroidism are at risk for hypercalcemia and require monitoring during vitamin D repletion. [2]

Complicationstoggle arrow icon

Common complications

Conditions associated with adverse outcomes in vitamin D deficiency [8]

To prevent complications, patients with the following conditions may benefit from maintaining a higher vitamin D level (≥ 30 ng/mL).

We list the most important complications. The selection is not exhaustive.

Preventiontoggle arrow icon

  • Vitamin D deficiency prevention relies on adequate dietary intake of vitamin D, as recommended sunscreen for skin cancer prevention prevents vitamin D from being synthesized in the skin. [2]
  • Intake may be in the form of foods and/or supplements (usually both). [8]
  • Foods high in vitamin D include: [3]
    • Fatty fish (salmon, sardines, mackerel, tuna)
    • Fish liver oil
    • Egg yolks
    • Vitamin-D fortified foods (e.g., milk, cereals, orange juice, yogurt)
  • Supplements are usually in the form of cholecalciferol or ergocalciferol. [2][25]
Age Recommended Vitamin D dietary intake [3]
< 1 year
  • ≥ 400 IU/day
  • Supplements containing the full amount are recommended for infants who: [3][6]
    • Are exclusively breastfed [2]
    • Consume less than 1 L (34 ounces) of formula per day
1–70 years
  • ≥ 600 IU/day
  • Higher values (≥ 1000 IU/day) may be appropriate for patients who are pregnant or lactating. [2][26][27]
> 70 years
  • ≥ 800 IU/day

Adults with ongoing risk factors for vitamin D deficiency may require 2–3 times the recommended daily intake (i.e., 1500–2000 IU/day). [2][28]

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Referencestoggle arrow icon

  1. $Contributor Disclosures - Vitamin D deficiency. None of the individuals in control of the content for this article reported relevant financial relationships with ineligible companies. For details, please review our full conflict of interest (COI) policy.
  2. Holick MF, Binkley NC, Bischoff-Ferrari HA, et al. Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2011; 96 (7): p.1911-1930.doi: 10.1210/jc.2011-0385 . | Open in Read by QxMD
  3. Institute of Medicine, Committee to Review Dietary Reference Intakes for Vitamin D and Calcium Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. National Academies Press ; 2011
  4. Jameson JL, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J. Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2). McGraw-Hill Education / Medical ; 2018
  5. Brenner M, Hearing VJ. The Protective Role of Melanin Against UV Damage in Human Skin. Photochem Photobiol. 2007; 84 (3): p.539-549.doi: 10.1111/j.1751-1097.2007.00226.x . | Open in Read by QxMD
  6. Wagner CL, Greer FR. Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents. Pediatrics. 2008; 122 (5): p.1142-1152.doi: 10.1542/peds.2008-1862 . | Open in Read by QxMD
  7. Bilezikian JP, Brandi ML, Cusano NE, et al. Management of Hypoparathyroidism: Present and Future. J Clin Endocrinol Metab. 2016; 101 (6): p.2313-2324.doi: 10.1210/jc.2015-3910 . | Open in Read by QxMD
  8. Bilezikian JP, Formenti AM, Adler RA, et al. Vitamin D: Dosing, levels, form, and route of administration: Does one approach fit all?. Rev Endocr Metab Disord. 2021; 22 (4): p.1201-1218.doi: 10.1007/s11154-021-09693-7 . | Open in Read by QxMD
  9. Holick MF. Vitamin D Deficiency. N Engl J Med. 2007; 357 (3): p.266-281.doi: 10.1056/nejmra070553 . | Open in Read by QxMD
  10. Wang Z, Schuetz EG, Xu Y, Thummel KE. Interplay between vitamin D and the drug metabolizing enzyme CYP3A4. J Steroid Biochem Mol Biol. 2012; 136: p.54-58.doi: 10.1016/j.jsbmb.2012.09.012 . | Open in Read by QxMD
  11. Blaney SM, Giardino AP, Orange JS, et al. Rudolph's Pediatrics, 23rd Edition. McGraw-Hill Education / Medical ; 2018
  12. Kennel KA, Drake MT, Hurley DL. Vitamin D Deficiency in Adults: When to Test and How to Treat. Mayo Clinic Proceedings. 2010; 85 (8): p.752-758.doi: 10.4065/mcp.2010.0138 . | Open in Read by QxMD
  13. Misra M, Pacaud D, Petryk A, Collett-Solberg PF, Kappy M. Vitamin D Deficiency in Children and Its Management: Review of Current Knowledge and Recommendations. Pediatrics. 2008; 122 (2): p.398-417.doi: 10.1542/peds.2007-1894 . | Open in Read by QxMD
  14. Carpenter TO, Shaw NJ, Portale AA, Ward LM, Abrams SA, Pettifor JM. Rickets. Nat Rev Dis Primers. 2017; 3 (1).doi: 10.1038/nrdp.2017.101 . | Open in Read by QxMD
  15. Amrein K, Scherkl M, Hoffmann M, et al. Vitamin D deficiency 2.0: an update on the current status worldwide. Eur J Clin Nutr. 2020; 74 (11): p.1498-1513.doi: 10.1038/s41430-020-0558-y . | Open in Read by QxMD
  16. LeFevre ML, LeFevre NM. Vitamin D Screening and Supplementation in Community-Dwelling Adults: Common Questions and Answers.. Am Fam Physician. 2018; 97 (4): p.254-260.
  17. LeBoff MS, Greenspan SL, Insogna KL, et al. The clinician’s guide to prevention and treatment of osteoporosis. Osteoporos Int. 2022.doi: 10.1007/s00198-021-05900-y . | Open in Read by QxMD
  18. Rosen CJ, Abrams SA, Aloia JF, et al. IOM Committee Members Respond to Endocrine Society Vitamin D Guideline. J Clin Endocrinol Metab. 2012; 97 (4): p.1146-1152.doi: 10.1210/jc.2011-2218 . | Open in Read by QxMD
  19. Giustina A, Bouillon R, Binkley N, et al. Controversies in Vitamin D: A Statement From the Third International Conference. JBMR Plus. 2020; 4 (12).doi: 10.1002/jbm4.10417 . | Open in Read by QxMD
  20. Don’t routinely measure 1,25-dihydroxyvitamin D unless the patient has hypercalcemia or decreased kidney function.. Updated: October 16, 2013. Accessed: December 7, 2022.
  21. Uday S, Högler W. Nutritional Rickets and Osteomalacia in the Twenty-first Century: Revised Concepts, Public Health, and Prevention Strategies. Curr Osteoporos Rep. 2017; 15 (4): p.293-302.doi: 10.1007/s11914-017-0383-y . | Open in Read by QxMD
  22. Camacho PM, Petak SM, Binkley N, et al. American Association of Clinical Endocrinologists/American College of Endocrinology Clinical Practice Guidelines for the Diagnosis and Treatment of Postmenopausal Osteoporosis—2020 Update. Endocr Pract. 2020; 26 (Supp 1): p.1-46.doi: 10.4158/gl-2020-0524suppl . | Open in Read by QxMD
  23. Minisola S, Colangelo L, Pepe J, Diacinti D, Cipriani C, Rao SD. Osteomalacia and Vitamin D Status: A Clinical Update 2020. JBMR Plus. 2020; 5 (1).doi: 10.1002/jbm4.10447 . | Open in Read by QxMD
  24. Levine MA. Diagnosis and Management of Vitamin D Dependent Rickets. Front Pediatr. 2020; 8.doi: 10.3389/fped.2020.00315 . | Open in Read by QxMD
  25. ACOG. Committee Opinion No. 495: Vitamin D: Screening and Supplementation During Pregnancy. Obstetrics & Gynecology. 2011; 118 (1): p.197-198.doi: 10.1097/aog.0b013e318227f06b . | Open in Read by QxMD
  26. Pérez-López FR, Pilz S, Chedraui P. Vitamin D supplementation during pregnancy: an overview. Curr Opin Obstet Gynecol. 2020; 32 (5): p.316-321.doi: 10.1097/gco.0000000000000641 . | Open in Read by QxMD
  27. Holick MF. The vitamin D deficiency pandemic: Approaches for diagnosis, treatment and prevention. Rev Endocr Metab Disord. 2017; 18 (2): p.153-165.doi: 10.1007/s11154-017-9424-1 . | Open in Read by QxMD
  28. Krist AH, Davidson KW, et al. Screening for Vitamin D Deficiency in Adults. JAMA. 2021; 325 (14): p.1436.doi: 10.1001/jama.2021.3069 . | Open in Read by QxMD

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