Vitamin D Deficiency in Women in Saudi Arabia: Symptoms, Testing and Treatment

Vitamin D deficiency can be easy to miss. You may have no symptoms, or you may notice deep bone discomfort, weak thigh muscles, or difficulty rising from a chair. Tiredness alone is not enough to identify it. In Saudi Arabia, low vitamin D is common among people who have been tested, but that does not mean every woman needs a screening test or a high-dose supplement.

This guide explains the local picture, which symptoms deserve assessment, when a 25-hydroxyvitamin D test is appropriate, and how clinicians treat confirmed deficiency. It also separates the 2024 Endocrine Society prevention guideline from older treatment guidance, so you do not mistake advice for generally healthy people for a treatment plan.

Medical note: This article is educational. It cannot diagnose the cause of your symptoms or select a safe supplement dose for you. Pregnancy, kidney or parathyroid disease, malabsorption, granulomatous disease, high calcium, and some medicines change how vitamin D should be assessed and treated.

Key takeaways

• Vitamin D deficiency in women in Saudi Arabia is a genuine local health issue. In a 2019 study of 166 Riyadh women aged 30 to 65, 60.2% had a 25(OH)D result below 20 ng/mL. A larger Riyadh Region dataset of people already tested found substantial low-level prevalence, but neither study estimates the rate in every Saudi woman (Scientific Reports, 2019; Frontiers in Public Health, 2025).
• Bone pain, osteomalacia, and proximal muscle weakness are the clearest clinical concerns. Fatigue is nonspecific and can have many other causes (NIH Office of Dietary Supplements; USPSTF).
• The correct status test is serum 25-hydroxyvitamin D, written as 25(OH)D. The active hormone test, 1,25-dihydroxyvitamin D, is not a routine status test (NIH Office of Dietary Supplements).
• Routine testing of healthy, symptom-free adults is not recommended by Saudi CHI criteria. The 2024 Endocrine Society guideline also advises against routine testing in generally healthy adults, including during pregnancy, for disease prevention (Saudi CHI testing criteria; Endocrine Society, 2024).
• Treatment doses are not the same as routine nutritional intake. Saudi CHI algorithms include clinician-supervised loading regimens for defined situations, followed by reassessment and maintenance. They are not instructions to self-start 50,000 IU capsules (Saudi CHI treatment algorithm).
• Too much vitamin D can raise calcium and injure the kidneys. Nausea, vomiting, marked thirst, frequent urination, dehydration, confusion, weakness, or an irregular heartbeat after high-dose use need prompt medical attention (NIH Office of Dietary Supplements).

What vitamin D deficiency means

Vitamin D deficiency is a low vitamin D state that can impair calcium and phosphate balance and, when severe or prolonged, contribute to osteomalacia, a softening of adult bone. Clinicians assess vitamin D status with serum 25(OH)D because it reflects vitamin D made in the skin and obtained from food or supplements. It has a circulating half-life of about 15 days (NIH Office of Dietary Supplements).

Vitamin D helps the intestine absorb calcium and supports normal mineralisation of bone. If a marked deficiency persists, the body may struggle to maintain normal bone mineralisation. Adults can develop diffuse bone pain, tenderness, and muscle weakness. The active form of vitamin D has wider biological actions, but a receptor in a tissue does not prove that supplements will treat every condition associated with a low blood result.

The test name matters

Ask whether the laboratory measured 25-hydroxyvitamin D, or 25(OH)D. A 1,25-dihydroxyvitamin D result is not a substitute for routine vitamin D status assessment because the body tightly regulates it and it may remain normal until deficiency is severe. Clinicians reserve that active-hormone test for selected disorders, such as particular kidney, calcium, parathyroid, or granulomatous conditions (NIH Office of Dietary Supplements).

Results may be reported in ng/mL or nmol/L. The conversion is 1 ng/mL = 2.5 nmol/L. Laboratory methods can also disagree, so a number should be read with the units, assay, symptoms, medical history, and the clinical reason for testing (NIH Office of Dietary Supplements). A separate result-interpretation page should own the full number-by-number explanation.

Why is vitamin D deficiency common in Saudi Arabia?

Strong sunshine does not guarantee adequate vitamin D. Vitamin D production depends on UVB reaching uncovered skin, while everyday life in Riyadh often involves indoor work, car travel, heat avoidance, and clothing that limits skin exposure. Skin pigmentation, age, body size, diet, medicines, and medical conditions can also affect status.

A 2019 study of 166 women aged 30 to 65 in Riyadh found that 60.2% had a 25(OH)D concentration below 20 ng/mL and 28.9% were below 10 ng/mL. It was a relatively small study, conducted in 2015 and 2016, so its percentage should not be applied to every woman in the city or country (Scientific Reports, 2019).

A 2025 report examined 22,335 people tested in a Riyadh Region hospital and community dataset from 2017 to 2021. Among those tested, 67.3% had results below 30 ng/mL, 35.9% were between 7 and under 20 ng/mL, and 3.3% were below 7 ng/mL. Women made up 69.9% of the tested group. Because clinicians and patients often order tests when risk is already suspected, these figures describe a tested population rather than national prevalence (Frontiers in Public Health, 2025).

Factors that can increase risk

The NIH Office of Dietary Supplements and Saudi CHI testing criteria identify several contexts that can make low vitamin D more likely or make its consequences more clinically important:

• little direct outdoor skin exposure because of indoor routines, sun avoidance, or extensive clothing coverage;
• darker skin pigmentation, which reduces cutaneous vitamin D production for a given UVB exposure;
• older age, when the skin becomes less efficient at producing vitamin D;
• obesity, because circulating 25(OH)D is often lower and treatment requirements may differ;
• fat malabsorption, including coeliac disease, Crohn's disease, ulcerative colitis, cystic fibrosis, or a history of bariatric surgery;
• chronic kidney or liver disease;
• calcium, phosphate, or parathyroid disorders;
• osteoporosis, a fragility fracture, or a high fracture risk;
• medicines that alter vitamin D metabolism or absorption, including some anticonvulsants, long-term glucocorticoids, rifampicin, cholestyramine, certain antifungals, and orlistat.

Clothing is one factor, not a diagnosis and not a fault. A woman who dresses with extensive skin coverage can meet her vitamin D needs without changing how she dresses. The practical plan may involve food, an appropriate routine supplement, or clinician-guided treatment if deficiency is confirmed. Detailed intake choices belong in the dedicated guide on getting vitamin D with limited sun exposure.

No safe, universal number of sun minutes can be prescribed. UV index, season, time of day, skin tone, age, area of skin exposed, and personal skin-cancer risk all change the equation. The American Academy of Dermatology does not recommend obtaining vitamin D through unprotected UV exposure, so this page does not advise skipping sunscreen or tanning (American Academy of Dermatology).

What are the symptoms of vitamin D deficiency in women?

Many women with a low result have no obvious symptoms. When deficiency is clinically significant, the more specific concerns are bone pain, bone tenderness, and proximal muscle weakness, such as difficulty rising from a chair, climbing stairs, or walking. Symptoms alone cannot confirm the diagnosis. (NIH Office of Dietary Supplements; USPSTF)

Symptoms that support medical assessment

• diffuse or deep bone discomfort, especially when persistent or affecting movement;
• tenderness over bone;
• weakness around the hips and thighs, sometimes noticed when standing from a low seat or climbing stairs;
• difficulty walking, a waddling gait, or falls when weakness is marked;
• a fragility fracture, meaning a fracture after a low-impact event;
• muscle cramps, tingling, or spasms when a calcium disturbance may be present.

Severe, prolonged deficiency can cause osteomalacia in adults. This is different from osteoporosis. Osteomalacia means bone has not mineralised normally, while osteoporosis refers mainly to reduced bone mass and altered bone structure. They can coexist, but the assessment and treatment questions are not identical.

Symptoms that are too broad to diagnose deficiency

Fatigue, vague aches, headaches, hair shedding, low mood, poor sleep, and reduced concentration are real symptoms, but they occur in many conditions. Iron deficiency, anaemia, thyroid disorders, sleep problems, depression, medication effects, chronic pain conditions, and pregnancy-related changes can look similar. A vitamin D test may be reasonable when the wider history supports it, but a symptom checklist cannot tell you which diagnosis is correct.

If low mood is your main concern, vitamin D should not replace a mental-health assessment or evidence-based treatment. If fertility is your concern, a vitamin D result cannot measure ovarian reserve, egg quality, or the chance of pregnancy. Those questions belong in the collection's dedicated mood and fertility pages.

Who should have a vitamin D test in Saudi Arabia?

Testing should be indication-based, not automatic. Saudi CHI criteria state that routine testing of asymptomatic people is not recommended. A test is more reasonable when symptoms, a relevant disease, a medicine, or a bone-health risk would change clinical management. (Saudi CHI testing criteria)

The CHI indication list includes BMI over 30, age 65 or older, malabsorption or bariatric surgery, chronic kidney or liver disease, parathyroid and calcium or phosphate disorders, granulomatous disease, long-term glucocorticoids, several medicine classes, selected restrictive diets, deeply pigmented skin, documented proximal muscle weakness, autoimmune disease, and high fracture risk. (Saudi CHI testing criteria).

The USPSTF concludes that evidence is insufficient to judge the benefits and harms of screening asymptomatic adults. “Insufficient evidence” does not mean the test is useless. It means there is no proven net benefit for screening people without signs or symptoms. Diagnostic testing for bone pain, weakness, suspected osteomalacia, or a relevant medical condition sits outside that screening question.

What happens during assessment?

A useful assessment starts before the blood draw. The clinician needs to understand why deficiency is suspected and whether the result would change management.

1. Symptom history. Expect questions about bone pain, muscle weakness, falls, fractures, cramps, walking, and the effect on daily activities. Fatigue or hair shedding should trigger a broader differential rather than a vitamin D assumption.
2. Risk review. This includes time spent outdoors, skin coverage, diet, pregnancy or breastfeeding, menopause, bariatric surgery, bowel disease, kidney or liver disease, fracture history, and medicines or supplements.
3. Examination when indicated. A clinician may assess gait, proximal strength, bone tenderness, hydration, or signs of calcium disturbance.
4. 25(OH)D measurement. This is the main status test. Fasting is not inherently required for 25(OH)D, although another test ordered at the same time may have its own preparation rules.
5. Targeted additional tests. Calcium, phosphate, kidney function, alkaline phosphatase, or parathyroid hormone may be useful when deficiency is severe, symptoms suggest osteomalacia or a calcium problem, or treatment risk is higher. They are not a mandatory “full panel” for every patient.
6. Imaging only for a reason. A suspected fracture may require an X-ray. Bone-density testing answers an osteoporosis question and is not a routine confirmation test for vitamin D deficiency.

What level counts as vitamin D deficiency?

There is no single international cut-off for every clinical purpose. The US Food and Nutrition Board framework used by the NIH describes less than 12 ng/mL, or less than 30 nmol/L, as deficient and associated with rickets or osteomalacia risk; 12 to under 20 ng/mL as generally inadequate; and at least 20 ng/mL as generally adequate for most people. It warns that results above 50 ng/mL, or 125 nmol/L, may be associated with adverse effects (NIH Office of Dietary Supplements).

For Saudi clinical context, the November 2023 CHI formulary algorithm uses 20 ng/mL or lower as deficiency and describes a maintenance range of 30 to 50 ng/mL. It also uses different treatment pathways for results below 12 ng/mL and for 12 to under 20 ng/mL without symptoms (Saudi CHI treatment algorithm).

This page intentionally stops at that summary. If you already have a report, the dedicated guide Vitamin D Blood Test Results: 25(OH)D Levels Explained covers units, assay variation, and borderline results.

How the 2011 and 2024 Endocrine Society guidelines differ

Confusion often comes from citing “the Endocrine Society guideline” without a year or population.

The 2011 guideline focused on evaluating, treating, and preventing vitamin D deficiency. It supplied deficiency definitions and treatment regimens for people at risk or already deficient. The Endocrine Society states that its 2024 guideline replaces the 2011 document for vitamin D use to prevent disease in people without established indications (Endocrine Society, 2024).

The 2024 guideline asks a different question: should generally healthy people take vitamin D above the recommended dietary allowance, or undergo routine blood testing, to reduce disease risk? It suggests against routine 25(OH)D testing in generally healthy adults, including people with dark complexion, obesity, and pregnancy. It also says clinical-trial evidence did not establish outcome-specific target blood concentrations for disease prevention (Endocrine Society guideline in JCEM, 2024).

That does not mean clinicians should ignore suspected osteomalacia, symptomatic muscle weakness, malabsorption, abnormal calcium, kidney disease, or a documented low result. It means population prevention, diagnostic assessment, and treatment of established deficiency are separate jobs. Saudi CHI criteria and the CHI formulary algorithm remain the local sources used here for indication-based testing and treatment context.

The 2024 guideline also prefers daily lower-dose vitamin D over intermittent higher-dose vitamin D in adults aged 50 or older who have an indication for supplementation or treatment. This is a conditional recommendation based on low-certainty evidence, not proof that every weekly regimen is unsafe (Endocrine Society guideline in JCEM, 2024).

How is confirmed vitamin D deficiency treated?

Treatment is chosen from the result, symptoms, cause, age, pregnancy status, kidney function, calcium balance, medicines, and likelihood of absorption. Oral vitamin D is commonly used, but a loading dose is a prescription context, not a wellness routine.

The November 2023 Saudi CHI algorithm describes cholecalciferol, or vitamin D3, treatment according to severity. For a level below 12 ng/mL, or for symptomatic or hypocalcaemic patients, it documents 50,000 IU weekly, or a daily equivalent, for 6 to 12 weeks followed by reassessment. For a level from 12 to under 20 ng/mL without symptoms, it documents 800 to 1,000 IU daily for about three to four months. The algorithm also lists 6,000 IU daily for adult deficiency and up to 10,000 IU daily in obesity or malabsorption contexts, with maintenance after correction (Saudi CHI treatment algorithm).

Those numbers report a guideline. They are not instructions for self-treatment. A clinician has to reconcile overlapping pathways in the algorithm, check whether the patient fits the population, and decide whether calcium, kidney function, or other monitoring is needed. A person with granulomatous disease, hypercalcaemia, hyperparathyroidism, or severe renal impairment should not use a standard pathway without specialist input (Saudi CHI testing criteria).

What treatment should accomplish

The goal is not to chase the highest possible blood number. Treatment should correct the deficiency, protect bone and muscle, address an underlying cause where possible, and avoid excess calcium. If a medicine or malabsorption is driving the problem, supplementation alone may not solve it.

Response should be assessed clinically as well as biochemically. Persistent fatigue, pain, weakness, or hair loss deserves reassessment for other causes. There is no guaranteed week when a woman will feel better, and bone recovery can take longer than correction of the blood result.

Medicines and supplement interactions

Orlistat can reduce vitamin D absorption. Corticosteroids can impair vitamin D metabolism and calcium absorption. Thiazide diuretics can increase the risk of hypercalcaemia when combined with vitamin D, especially in older adults or people with compromised kidney function. High vitamin D intake can also affect some statin medicines. Review your complete medication list with a pharmacist or clinician before treatment (NIH Office of Dietary Supplements).

Avoid stacking products. A prescribed capsule, multivitamin, calcium and vitamin D tablet, drops, and cod-liver oil may all contribute to the same daily total. The label should be checked in IU and micrograms, noting that 1 microgram of vitamin D equals 40 IU (NIH Office of Dietary Supplements).

Vitamin D deficiency in pregnancy

Pregnancy needs careful wording because recommendations address different questions. The 2024 Endocrine Society guideline suggests empiric vitamin D supplementation during pregnancy to reduce certain pregnancy risks, yet suggests against routine 25(OH)D testing in generally healthy pregnant people. It also notes that trials used many different doses and did not establish a single optimal blood target (Endocrine Society guideline in JCEM, 2024).

The US recommended dietary allowance during pregnancy is 600 IU, or 15 micrograms, daily. That is a nutritional reference intake, not a treatment dose for a confirmed deficiency (NIH Office of Dietary Supplements). Prenatal vitamins differ, and the total should include every supplement.

A pregnant woman with suspected or confirmed deficiency should have her plan coordinated with her maternity clinician. The Saudi CHI document specifically places pregnancy and lactation management under specialist oversight (Saudi CHI testing criteria). Do not copy a high-dose adult regimen into pregnancy, and do not delay obstetric assessment while trying to correct a vitamin result.

Severe headache, visual changes, upper abdominal pain, marked swelling, bleeding, shortness of breath, or reduced fetal movement are not “vitamin D symptoms.” They require urgent maternity assessment according to gestational stage and local emergency advice.

Calcium, kidneys, and vitamin D toxicity

Vitamin D and calcium are connected, but they are not automatically a package. Vitamin D increases calcium absorption. A clinician may review dietary calcium and may measure blood calcium when deficiency is severe, symptoms suggest a disturbance, or high-dose treatment increases risk. That does not mean every patient needs a calcium supplement.

Extra calcium can cause constipation and may add to kidney-stone or hypercalcaemia risk in susceptible people. The decision should consider food intake, total supplemental calcium, stone history, kidney function, and any parathyroid disorder. The dedicated calcium guide should own daily requirements and supplement selection.

For generally healthy adults, the US tolerable upper intake level for vitamin D is 4,000 IU, or 100 micrograms, per day. A tolerable upper level is not a treatment ceiling and not a recommended target. Clinicians sometimes prescribe more for a limited period to treat deficiency, but that requires an indication and monitoring (NIH Office of Dietary Supplements).

Vitamin D toxicity is almost always caused by excessive supplement intake, not ordinary sun exposure. It produces hypercalcaemia. The NIH describes toxicity as typically involving very high 25(OH)D concentrations, often above 150 ng/mL or 375 nmol/L, alongside high calcium. A blood vitamin D result alone does not diagnose toxicity, and 150 nmol/L is not the same as 150 ng/mL (NIH Office of Dietary Supplements).

Possible toxicity symptoms include nausea, vomiting, poor appetite, constipation, pronounced weakness, confusion, dehydration, excessive thirst, frequent urination, and kidney stones. Extreme toxicity can cause kidney failure, calcification of soft tissues, and abnormal heart rhythms. Stop non-essential vitamin D supplements and obtain urgent medical advice if these symptoms develop after high-dose use (NIH Office of Dietary Supplements).

What follow-up looks like

Follow-up should answer three questions: did the level respond, is treatment safe, and was the cause addressed?

Saudi CHI criteria describe rechecking 25(OH)D four to six months after a loading regimen and say monitoring should not exceed three tests in a year. The CHI treatment algorithm also instructs reassessment after a 6 to 12 week high-dose course. These timings reflect different documents and clinical pathways, so the prescriber should set the date rather than the patient ordering repeated tests independently (Saudi CHI testing criteria; Saudi CHI treatment algorithm).

A follow-up may include:

• adherence and the exact product used;
• total vitamin D from all supplements;
• improvement, persistence, or worsening of bone pain and muscle weakness;
• calcium or kidney tests when clinically indicated;
• evidence of malabsorption, an interacting medicine, or another ongoing cause;
• a maintenance plan if the original risk remains.

Do not expect a guaranteed symptom timeline. If the blood result improves but fatigue remains, that is useful information. It tells the clinician to look beyond vitamin D rather than endlessly increasing the dose.

When to seek urgent care

Seek urgent medical assessment, or emergency care if symptoms are severe, for:

• a suspected fracture, especially after a minor fall or movement;
• new inability to stand or walk, rapidly worsening weakness, or repeated falls;
• severe muscle spasms, facial twitching, or spasms of the hands or feet, which can occur with a significant calcium disturbance;
• fainting, confusion, severe dehydration, persistent vomiting, or an irregular heartbeat;
• marked thirst and frequent urination after taking high-dose vitamin D, particularly with weakness, nausea, or kidney pain;
• severe pregnancy symptoms such as reduced fetal movement, bleeding, severe headache, visual changes, upper abdominal pain, marked swelling, or shortness of breath.

Do not wait for a vitamin D appointment if you may have a fracture, dangerous calcium disturbance, kidney injury, heart-rhythm problem, or obstetric emergency. In Saudi Arabia, use the appropriate local emergency service or maternity assessment unit.

For non-emergency bone pain, proximal muscle weakness, a relevant medical condition, or concerns after high-dose supplementation, arrange a timely assessment with a licensed clinician.

Questions to take to an appointment

A short list can make the consultation more useful:

1. Was my test 25(OH)D, and which units did the laboratory use?
2. Is this diagnostic testing for a symptom or disease, or screening without an indication?
3. Which threshold framework are you using, and why does it fit my situation?
4. Do my symptoms suggest osteomalacia, a calcium problem, or another diagnosis?
5. Should calcium, kidney function, phosphate, alkaline phosphatase, or parathyroid hormone be checked?
6. Does pregnancy, bariatric surgery, bowel disease, kidney disease, obesity, or a medicine change the plan?
7. What is the total vitamin D in all my products?
8. When should treatment stop, change to maintenance, or be reassessed?
9. What symptoms should make me seek urgent care?

Myths that can lead to the wrong decision

Myth: “Saudi sunshine means deficiency is impossible.”
Fact: UVB must reach skin, and everyday exposure varies. Riyadh studies show low results are common among tested women, but they do not justify testing every symptom-free person (Scientific Reports, 2019; Frontiers in Public Health, 2025).

Myth: “Fatigue proves my vitamin D is low.”
Fact: Fatigue is nonspecific. Bone pain and proximal weakness provide a stronger reason to consider deficiency, while iron, thyroid, sleep, mood, medication, and other causes may need assessment.

Myth: “Everyone should aim above 30 ng/mL.”
Fact: Thresholds depend on the framework and purpose. The 2024 Endocrine Society prevention guideline did not establish outcome-specific targets for generally healthy people (Endocrine Society, 2024).

Myth: “A 50,000 IU capsule is a safe weekly wellness dose.”
Fact: Saudi CHI documents high-dose courses for defined deficiency contexts under clinician supervision. The dose can be harmful if the diagnosis, duration, calcium balance, kidney function, or other supplements are not considered (Saudi CHI treatment algorithm).

Myth: “More testing is always safer.”
Fact: Routine screening can label borderline values without improving outcomes, and assay variation can produce misleading differences. Test when the result can guide a clinical decision (USPSTF).

Myth: “I should stop sunscreen and expose my skin for a fixed number of minutes.”
Fact: There is no fixed exposure prescription that fits every person. Do not trade deficiency prevention for UV damage; use skin-safe intake strategies instead (American Academy of Dermatology).

Myth: “Saudi sunshine means deficiency is impossible.”
Fact: UVB must reach skin, and everyday exposure varies. Riyadh studies show low results are common among tested women, but they do not justify testing every symptom-free person (Scientific Reports, 2019; Frontiers in Public Health, 2025).

Myth: “Fatigue proves my vitamin D is low.”
Fact: Fatigue is nonspecific. Bone pain and proximal weakness provide a stronger reason to consider deficiency, while iron, thyroid, sleep, mood, medication, and other causes may need assessment.

Myth: “Everyone should aim above 30 ng/mL.”
Fact: Thresholds depend on the framework and purpose. The 2024 Endocrine Society prevention guideline did not establish outcome-specific targets for generally healthy people (Endocrine Society, 2024).

Myth: “A 50,000 IU capsule is a safe weekly wellness dose.”
Fact: Saudi CHI documents high-dose courses for defined deficiency contexts under clinician supervision. The dose can be harmful if the diagnosis, duration, calcium balance, kidney function, or other supplements are not considered (Saudi CHI treatment algorithm).

Myth: “More testing is always safer.”
Fact: Routine screening can label borderline values without improving outcomes, and assay variation can produce misleading differences. Test when the result can guide a clinical decision (USPSTF).

Myth: “I should stop sunscreen and expose my skin for a fixed number of minutes.”
Fact: There is no fixed exposure prescription that fits every person. Do not trade deficiency prevention for UV damage; use skin-safe intake strategies instead (American Academy of Dermatology).

Frequently asked questions

The bottom line

Vitamin D deficiency deserves attention when it affects bone, muscle, calcium balance, or a condition that changes vitamin D metabolism. The Saudi context matters because low results are common in tested populations and daily sun exposure can be limited even in a sunny climate. Yet prevalence is not a reason to diagnose yourself from fatigue or order repeated screening without an indication.

If symptoms or risk factors make testing appropriate, confirm that the test is 25(OH)D. Ask which threshold framework applies. Treatment should match the result and your medical context, with a plan for safety and follow-up. Do not self-start high-dose vitamin D, especially during pregnancy or if you have kidney, parathyroid, calcium, absorption, or granulomatous disease.

A licensed clinician can help decide whether assessment is appropriate. Seek urgent care for fracture, severe weakness, spasms, confusion, dehydration, abnormal heartbeat symptoms, or serious pregnancy concerns.

References

1. National Institutes of Health Office of Dietary Supplements. Vitamin D: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
2. Endocrine Society. Vitamin D for the Prevention of Disease: Clinical Practice Guideline. 2024. https://www.endocrine.org/clinical-practice-guidelines/vitamin-d-for-prevention-of-disease
3. Demay MB, Pittas AG, Bikle DD, et al. Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology & Metabolism. 2024;109(8):1907-1947. https://academic.oup.com/jcem/article/109/8/1907/7685305
4. US Preventive Services Task Force. Screening for Vitamin D Deficiency in Adults. 2021. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/vitamin-d-deficiency-screening
5. Council of Health Insurance, Saudi Arabia. Criteria for Insurance Coverage for Vitamin D Testing. https://www.chi.gov.sa/en/aboutchi/cchiprograms/MedicineDocuments/Vitamin%20D.pdf
6. Council of Health Insurance, Saudi Arabia. Vitamin D Deficiency Treatment Algorithm, Formulary Appendix 47. November 2023. https://www.chi.gov.sa/Style%20Library/IDF_Branding/PdfTab/Appendix%2047%20-%20Vitamin%20D%20Deficiency%20Treatment%20Algorithm.pdf
7. Riyadh women vitamin D study. Scientific Reports. 2019. https://www.nature.com/articles/s41598-019-56830-z
8. Five-year trends of vitamin D status in the Riyadh Region, Saudi Arabia. Frontiers in Public Health. 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12066668/
9. American Academy of Dermatology. Vitamin D and UV exposure. https://www.aad.org/media/stats-vitamin-d
10. National Institutes of Health Office of Dietary Supplements. Calcium: Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/