A three-stage family medicine approach to unmasking vitamin D deficiency in a post-COVID-19 prediabetes patient

Abstract

Vitamin D is essential for musculoskeletal health, and deficiency is frequently linked to pain and weakness. While low vitamin D levels worsen acute Coronavirus disease 2019 (COVID-19) outcomes, their role in post-COVID symptom recovery remains unclear. The American Diabetes Association recommends diabetes screening from age 35, with earlier screening for overweight adults with risk factors. This case study aims to report an occult case of vitamin D deficiency among post-COVID-19 prediabetes patients through the lens of a case study using the three-stage family medicine approach following the CAse REport (CARE) checklist. A 50-year-old woman presented with right forearm pain for two weeks and intermittent numbness in the same arm for two months after recovering from COVID-19. Through clinical, individual, and contextual assessments, neurological and structural causes were excluded, revealing severe vitamin D deficiency (10 ng/mL) and incidental prediabetes (HbA1c 5.9%). Her symptoms were influenced by sedentary post-pandemic behaviour, emotional stress, and limited local healthcare access. Management included non-steroidal anti-inflammatory drugs for symptom relief, high-dose vitamin D supplementation (60,000 IU weekly for 8–12 weeks), lifestyle modification, and psychosocial support, demonstrating the value of holistic care in primary practice. This case illustrates how the three-stage family medicine approach aids in identifying metabolic and nutritional contributors to nonspecific musculoskeletal complaints, addressing patient concerns, and guiding shared management, especially in resource-limited settings. Despite being a single case, it highlights the importance of holistic, patient-centred care and early detection of modifiable risks such as vitamin D deficiency and prediabetes in post-COVID-19 patients.

Background

Vitamin D plays a crucial role in overall health, regulating calcium and phosphorus levels to support bone strength and nerve function. It also modulates both innate and adaptive immune responses, providing antimicrobial and antiviral support.[1,2,3] Beyond skeletal health, it aids muscle recovery, cellular turnover, and prevention of muscle atrophy, while alleviating nonspecific musculoskeletal pain and supporting neurocognitive and respiratory recovery.[4,5,6,7,8] According to Weir et al. (2020),[9] vitamin D also plays an important role in respiratory infections, as illustrated by the fact that low vitamin D levels are common in populations worldwide and have been associated with a significantly increased risk of pneumonia and viral upper respiratory tract infections. Vitamin D deficiency affects individuals of all ages, including infants, children, and adults, and is especially common in those with darker skin tones or limited sun exposure, such as in Middle Eastern populations.[1,2,3] Vitamin D deficiency is highly prevalent across Asia, particularly in South Asia, with rates exceeding 60% in countries such as India, Pakistan, and Bangladesh.[10,11,12] Jiang et al.[13] identified that in Asian populations, factors influencing vitamin D deficiency include gender, age, altitude, region, and diseases such as diabetes, cancer, fractures, and metabolic disorders. However, the exact prevalence remains unclear, highlighting the need for further research in diverse Asian populations, including Myanmar, to inform targeted interventions.[14,15]

Vitamin D is available in two forms: D2 (ergocalciferol) and D3 (cholecalciferol), with D3 being more effective and available over the counter. Recommended daily intake ranges from 10 mcg (400 IU) for infants to 15–20 mcg (600–800 IU) for adults, with higher supplementation advised for at-risk groups, such as older adults. Diagnosis is made through blood tests measuring 25-hydroxy (25-OH) vitamin D levels.[1,2,3] Low vitamin D levels are associated with peripheral neuropathy, with symptoms of numbness, tingling, and pain, particularly in weight-bearing and actively used muscles (e.g. arms in manual tasks).[3,6] Vitamin D deficiency negatively impacts the acute phase of Coronavirus disease 2019 (COVID-19), but its role in symptom recovery among survivors remains unclear.[16] However, excessive supplementation may cause toxicity, highlighting the need for medical guidance. Proactive measures to maintain optimal vitamin D levels are essential for long-term health and well-being. Dietary sources of vitamin D include oily fish (e.g. salmon, tuna, mackerel), beef liver, egg yolks, and fortified cereals. However, milk and dairy products contain little to no vitamin D, making food sources alone insufficient for many individuals and emphasising the need for supplementation in high-risk groups.[1,2]

The American Diabetes Association recommends diabetes screening for adults starting at age 35, with earlier screening advised for those who are overweight and have additional risk factors.[17] Common diagnostic tests for prediabetes include the haemoglobin A1C test, which reflects average blood sugar levels over the past two to three months. Results below 5.7% are considered normal, 5.7% to 6.4% indicate prediabetes, and 6.5% or higher on two tests confirms diabetes.[16,18] Managing prediabetes primarily involves lifestyle interventions. A balanced diet rich in fruits, vegetables, and whole grains, coupled with regular physical activity, can help stabilise blood sugar and reduce the risk of developing type 2 diabetes. Adults are encouraged to aim for at least 150 minutes of moderate exercise weekly, while children should engage in a minimum of one hour of physical activity daily. Weight loss, even modest reductions, significantly lowers diabetes risk.[16,18]

However, no cases of prediabetes case management have been reported from Myanmar. This case study aims to report an occult case of vitamin D deficiency among post-COVID-19 prediabetes patients through the lens of a case study using the three-stage family medicine approach following CAse REport (CARE) checklist [Supplementary Table 1].[19] The study outcome will provide a reproducible framework and comprehensive patient assessment for practitioners while highlighting the importance of investigating and managing overlooked deficiencies such as vitamin D in patients.

Supplementary Table 1.

		CARE Checklist of information to include when writing a case report
Topic	Item	Checklist item description	Reported
Title	1	The diagnosis or intervention of primary focus followed by the words “case report”	Page 1
Key Words	2	2 to 5 keywords that identify diagnoses or interventions in this case report, including "case report"	Page 1
Abstract (no references)	3a	Introduction: What is unique about this case and what does it add to the scientific literature?	Page 1
	3b	Main symptoms and/or important clinical findings	Page 1
	3c	The main diagnoses, therapeutic interventions, and outcomes	Page 1
	3d	Conclusion—What is the main “take-away” lesson(s) from this case?	Page 1
Introduction	4	One or two paragraphs summarizing why this case is unique (may include references)	Page 2-3
Patient Information	5a	De-identified patient specific information	Page 3-8
	5b	Primary concerns and symptoms of the patient	Page 3-8
	5c	Medical, family, and psycho-social history including relevant genetic information	Page 3-8
	5d	Relevant past interventions with outcomes	Page 3-8
Clinical Findings	6	Describe significant physical examination (PE) and important clinical findings	Page 3-8
Timeline	7	Historical and current information from this episode of care organized as a timeline	Page 3-8
Diagnostic Assessment	8a	Diagnostic testing (such as PE, laboratory testing, imaging, surveys)	Page 3-8
	8b	Diagnostic challenges (such as access to testing, financial, or cultural)	Page 3-8
	8c	Diagnosis (including other diagnoses considered)	Page 3-8
	8d	Prognosis (such as staging in oncology) where applicable	-
Therapeutic Intervention	9a	Types of therapeutic intervention (such as pharmacologic, surgical, preventive, self-care)	Page 3-8
	9b	Administration oftherapeutic intervention (such as dosage, strength, duration)	Page 3-8
Follow-up and Outcomes	9c	Changes in therapeutic intervention (with rationale)	-
	10a	Clinician and patient-assessed outcomes (if available)	Page 3-8
	10b	Important follow-up diagnostic and othertest results	Page 3-8
	10c	Intervention adherence and tolerability (How was this assessed?)	Page 3-8
	10d	Adverse and unanticipated events	Page 3-8
Discussion	11a	A scientific discussion of the strengths AND limitations associated with this case report	Page 9-10
	11b	Discussion of the relevant medical literature with references	Page 9-10
	11c	The scientific rationale for any conclusions (including assessment of possible causes)	Page 9-10
	11d	The primary “take-away” lessons of this case report (without references) in a one paragraph conclusion	Page 9-10
Patient Perspective	12	The patient should share their perspective in one to two paragraphs on the treatment(s) they received	Page 9-10
Informed Consent	13	Did the patient give informed consent? Please provide if requested

Case Report using Three Stages Assessment Approach

Stage 1. Clinical assessment

The patient under study is a 50-year-old woman who presents with right forearm pain for two weeks and intermittent numbness in the same arm for two months. The patient reports two months of progressively worsening numbness in the forearm, described as a tingling or crawling sensation, most noticeable in the mornings but resolving by evening without significantly affecting daily activities. Over the past two weeks, she developed gradual, throbbing pain in the upper arm and palm, exacerbated by arm movement but somewhat alleviated with rest, although paracetamol and massage provided no relief. She denies fever, chills, or weakness but attributes her symptoms partly to recent weight gain from a sedentary lifestyle. She observed that two months after recovering from coronavirus infection, she no longer feels the same strength or ease when lifting objects with both hands. She underwent a myomectomy procedure for leiomyoma last year. Her mother passed away during COVID-19 and had diabetes. She is divorced with two children, aged 22 and 18 years, and owns a women-only hair salon.

While reviewing the physical examination, her body mass index (BMI) indicated overweight at 29.6 kg/m², whereas her blood pressure and random blood sugar were normal. A deeper evaluation of her condition was needed to establish a definitive diagnosis. Her neurological and musculoskeletal examination showed no visible abnormalities such as scratches, redness, swelling, or muscle atrophy in her right hand. She reported pain during range-of-motion movements of the right forearm, including dorsiflexion, palmar flexion, supination, pronation, and deviations. However, she could perform these movements without issues when resistance was applied. Her ambulation, grip strength, and upper limb coordination were normal, with no motor deficits. Sensation testing with light touch and pinprick revealed no abnormalities, and she walked straight without difficulty. General examination and other system examinations revealed no significant findings. She had no history of smoking, alcohol consumption, or other substance abuse. The patient characteristics are presented in Table 1.

Table 1.

Characteristics of the study participant

Variables		Value/Status
Female
Age (years)		50
Weight (pound)		162
Height (feet, inches)		5′2″
BMI		29.6 kg/m2
Past medical history		Mild case of Coronavirus 10 months ago
Other chronic condition		No
Regular medication		No
Lifestyle		Sedentary
Presenting symptoms		• Two-week history of right forearm pain • Two-month history of on-and-off numbness in the same arm.
Presenting Signs		• The topical balm was applied to the right forearm due to pain. • No visible no scratch marks, no muscle atrophy, redness, or swelling. • No pain on touch but reported pain during range of motion in right forearm movement—dorsiflexion, palmar flexion, supination, pronation, ulnar deviation, radial deviation, accompanied by a distorted facial expression indicative of discomfort. • Full neurological assessment, no abnormality.
Investigations
X-ray of right forearm (anteroposterior and lateral)		No abnormality reported
HbA1C		5.9% *
Vitamin D (25-OH) levels		10 ng/mL **

BMI=Body mass index, *Range of HbA1C (Normal=below 5.7%, Prediabetes=between 5.7% and 64%, Diabetes=6.5% or higher). **Vitamin D (25-hydroxy) (Normal=30–50 ng/mL, Deficiency=less than 20 ng/ml

Stage 2. Individual Assessment using "P.R.I.C.E. S" Acronym

P: Personality patient was engaged and communicative. She attended alone but was joined by her daughter for the examination. She expressed sadness when discussing her mother’s death but no regret over her divorce, which was due to her husband’s infidelity. She takes pride in her new business and invests heavily in her work. While her adult children do not live with her, they visit frequently. She has no contact with her ex-husband.

R: Reason for Coming:

Her primary reason is to alleviate the pain and numbness in her right forearm while expressing concern about whether the condition might be serious.

I: Ideas and Thoughts about Sickness:

She shared that after recovering from coronavirus infection, she noticed a decline in her strength and ease when lifting objects with both hands. Initially, she did not take her early symptoms of numbness seriously and chose to ignore them. However, after experiencing severe pain in her right forearm, she felt the need to seek medical attention. She was concerned about whether she had any bone fractures.

C: Concerns and Fears:

During the consultation, she expressed concern that her symptoms might resemble those of her late mother, who had diabetes. She fears that she might suffer the same fate as her mother. Although she struggled in her early years following her divorce to cope with her emotions, she now feels stronger and able to face challenges in her life confidently.

E: Expectations:

Her expectation from the medical consultation was to clearly identify what was happening with her right forearm and to ensure that she did not have a serious condition.

S: Stress and Spiritual History:

Despite the challenges posed by political conflict and economic instability affecting her salon business, she finds satisfaction and fulfilment in running her independent enterprise. A devout Muslim, she actively engages in prayer as part of her spiritual practice. Over the past five years, she has adopted a partially vegetarian diet, abstaining from meat but consuming eggs. Following her divorce, she maintained a regular exercise routine, including yoga; however, she has experienced weight gain since the COVID-19 pandemic

Stage 3. Contextual Assessment

She lives in a town not directly affected by armed conflict but significantly impacted by political instability and economic hardship in Myanmar. The community faces high inflation, limited public healthcare, and reliance on costly private services for diagnostics and medications. Although the town is generally safe, there are limited public spaces for women to exercise, apart from a female-only gym, leading her to exercise at home. The town also has a reputation for drug-related issues and crime, contributing to broader social challenges. Despite financial strain, she remains emotionally resilient and optimistic. Since her divorce, she has avoided social media, communicating primarily via Messenger and Viber with close family members. As her mother’s only child, she maintains close relationships with three maternal cousins who provided strong support, particularly during the COVID-19 pandemic.

Following the three-stage assessment, selected investigations were performed due to limited diagnostic resources. These included a right forearm X-ray (anteroposterior and lateral views), HbA1c, complete blood count, vitamin D (25-OH), urea and electrolytes, liver and thyroid function tests, and routine urine analysis. The forearm X-ray showed no abnormalities. HbA1c was 5.9%, indicating prediabetes. Complete blood count, electrolyte levels, urine analysis, thyroid function, renal function, and liver function tests were all within normal limits. Vitamin D (25-OH) was markedly low at 10 ng/mL, indicating deficiency. Overall, the findings suggested good systemic health, with vitamin D deficiency and early glycaemic dysregulation requiring management.

Shared Management Plan - Three-stage Management Plan

Clinical management

Upon evaluating the patient’s symptoms of numbness and pain in the right forearm, several potential diagnoses were systematically ruled out. Cervical radiculopathy, carpal tunnel syndrome, ulnar nerve entrapment, and tendinitis were eliminated after considering the lack of specific neurological deficits and movement restrictions. Conditions such as brachial plexopathy, rheumatological disease such as systemic rheumatic diseases, and systemic lupus erythematosus were also excluded due to the absence of systemic signs such as joint inflammation or skin manifestations. The patient’s history and negative Adson’s test did not support a diagnosis of thoracic outlet syndrome. Psychogenic pain and post-viral Guillain–Barré syndrome were ruled out due to the lack of psychosomatic symptoms.

Two possible conditions related to diabetes were considered: peripheral neuropathy and post-COVID neuropathy, probably due to vitamin D deficiency or osteomalacia. Given her complaint of throbbing pain in the right forearm, non-steroidal anti-inflammatory drugs, such as ibuprofen 400 mg orally after meals, were prescribed along with cold applications for additional comfort. Her vitamin D level was significantly low (10 ng/mL), indicating a deficiency. Therefore, vitamin D supplementation with 60,000 IU of cholecalciferol weekly for 8–12 weeks was initiated. Regular two-week follow-ups were scheduled to monitor the effectiveness of treatment. The plan is to maintain a dose of 10,000 IU after rechecking patient’s vitamin D level. Additional recommendations included lifestyle modifications focusing on vitamin D-rich and management of prediabetes.

Individual Management using “P.R.I.C.E. S” Acronym

P: Personality:

Given her history of weight gain post-COVID-19 and emotional challenges related to her circumstances, it may be beneficial for her to have a close friend at the gym with whom she can exercise to address emotional distress and encourage adherence to her treatment plan. Her cousin also plays an important role in providing emotional support.

R: Reason for Coming:

Given her primary concern of pain and numbness in her right forearm, a comprehensive history and physical examination were conducted. The diagnosis of vitamin D deficiency was considered the likely cause of her forearm pain and numbness.

I: Ideas and Thoughts about Sickness:

The investigation results ruled out fractures or underlying bone pathology. The deficient vitamin D level suggests that her symptoms may be attributed to this deficiency, and lifestyle recommendations are important to prevent progression of the incidental finding of prediabetes.

C: Concerns and Fears:

Conversations centred on exploring potential solutions helped her understand that her current condition resulted from vitamin D deficiency and an incidental finding of prediabetes. Another concern for her was the possibility of developing diabetes, as experienced by her mother. Therefore, we first focused on understanding prediabetes and the importance of lifestyle modification, including weight management through healthy eating, regular physical activity (at least 150 minutes of moderate-intensity exercise per week), and monitoring blood sugar levels.

E: Expectations:

Her main expectation from the consultation was to receive a clear diagnosis regarding her forearm symptoms, which was achieved through the identification of vitamin D deficiency and incidental prediabetes. Motivational interviewing on lifestyle modification for prediabetes was conducted, effectively assuaging her anxiety and uncertainty about diabetes.

S: Stress and Spiritual History:

Despite the ongoing stress related to her salon business and political and economic challenges, she appears emotionally resilient, drawing strength from her spiritual practices. Encouraging continued participation in yoga and meditation can play a crucial role in her mental well-being. Since she has experienced weight gain post-COVID-19, I recommended focusing on a balanced diet through motivational interviewing, possibly with the support of a dietitian, to manage her weight and overall health. A partially vegetarian diet with adequate protein intake and increased vitamin D-rich foods such as egg yolks and fortified cereals may contribute to her physical and emotional health.

Contextual Management

She lives in a town with limited healthcare access, financial constraints, and unsafe conditions for outdoor exercise. Opportunities for lifestyle change were explored using motivational interviewing, focusing on home-based exercise and healthy eating through online resources. Following a comprehensive assessment, a shared decision-making approach was adopted to address her symptoms and concerns. Given her vitamin D deficiency and incidental prediabetes, a management plan was agreed upon, including cholecalciferol 60,000 IU weekly for 8–12 weeks with follow-up monitoring. Lifestyle modifications, such as a vitamin D-rich diet and regular physical activity, were emphasised, alongside continued yoga and meditation for stress management. This collaborative approach improved her understanding and empowered her to actively manage her health.

Discussion

This case highlights the complexity of assessing nonspecific musculoskeletal complaints within the broader context of a patient’s biological, psychological, and social circumstances. A 50-year-old woman presented with right forearm pain for two weeks and intermittent numbness in the same arm for two months after recovering from COVID-19. Using the three-stage family medicine approach, which includes clinical, individual, and contextual assessment, the evaluation ruled out neurological or structural causes [Figure 1]. It revealed significant vitamin D deficiency (10 ng/mL) and an incidental finding of prediabetes (HbA1c 5.9%). Her symptoms, combined with a sedentary post-pandemic lifestyle, emotional stressors, and limited access to healthcare resources, highlight the interplay between biological, psychological, and social determinants of health. A shared management plan was implemented, including symptomatic relief, vitamin D supplementation starting with cholecalciferol 60,000 IU weekly for 8–12 weeks, followed by regular follow-ups to monitor progress, lifestyle modification, and psychosocial support, demonstrating the value of holistic assessment in primary care.

Figure 1.

Three-stage assessment and management family medicine approach utilised for unmasking vitamin D deficiency in this study

The clinical findings in this case align with emerging evidence indicating that musculoskeletal pain, paraesthesia, and fatigue may be early manifestations of vitamin D deficiency, particularly among individuals with reduced sunlight exposure, limited physical activity, and prolonged indoor lifestyles following the COVID-19 pandemic.[6,20,21,22,23] Additionally, the identification of prediabetes fits with global trends showing rising metabolic risk among middle-aged women with sedentary habits and increased psychosocial stress.[24] The patient’s subjective concerns, fear of developing diabetes like her mother, emotional strain from divorce, and economic instability further highlight the value of the P.R.I.C.E.S. framework in capturing cognitive and emotional dimensions that shape clinical presentation and health-seeking behaviour.[25] Contextual factors also played a critical role in shaping this patient’s health status and management. Despite living in a non-conflict area, she faced political instability, inflation, limited access to public healthcare, and restricted safe spaces for women to engage in physical activity—barriers commonly faced in resource-constrained settings such as Myanmar.[26] The use of a family medicine approach and shared decision-making allowed her to understand her diagnosis, begin appropriate supplementation, adopt lifestyle modifications, and address her stress through continued spiritual practice, exercise, and dietary regulation.[27,28]

This case study has several limitations. It is based on a single patient encounter and may not be generalisable to broader populations. Diagnostic capacity was restricted due to limited local healthcare infrastructure, which constrained the ability to perform more advanced imaging or nerve conduction studies that might definitively exclude subtle neuropathic causes. The assessment relied partly on patient self-reporting, which may be subject to recall or interpretation bias. Additionally, the relationship between post-COVID-19 symptoms and vitamin D deficiency cannot be definitively established in a case study design. Nonetheless, this case demonstrates how the three-stage family medicine approach supports comprehensive, patient-centred care in real-world, low-resource contexts and highlights the importance of integrating clinical findings with individual experiences and contextual determinants of health. Future research should involve population-level screening to assess the prevalence of occult vitamin D deficiency among individuals recovering from COVID-19.

Conclusion

This case illustrates how a comprehensive family medicine approach can uncover underlying metabolic and nutritional contributors to nonspecific musculoskeletal symptoms, particularly in resource-constrained settings. By integrating clinical findings with individual beliefs, emotional concerns, and contextual realities, the three-stage assessment enabled accurate diagnosis, addressed patient fears, and guided a collaborative management plan. Although limited by single-patient data and restricted diagnostic resources, this case reinforces the importance of holistic, patient-centred care and early identification of modifiable risk factors such as vitamin D deficiency and prediabetes in post-COVID-19 patients. Despite the limitations inherent to a single-case design, including restricted diagnostics and reliance on self-reporting, this report demonstrates the utility of the three-stage family medicine approach for uncovering and managing occult deficiencies such as vitamin D in post-COVID care. This highlights the need for future population-level screening to assess its true prevalence.

Authorship contribution statement

HMT were involved in the conceptualisation, investigation, data curation, formal analysis, methodology, software and writing- original and final manuscripts.

Ethics statement and consent from participant

Informed consent (both oral and written) was obtained from the participant for publication of this case report, and all personal identifiers have been removed to ensure anonymity.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.