Nutrition Diet: What doctor checks your vitamins and minerals?

October 7, 2025 •

4 min read

According to the National Institutes of Health, significant portions of the population are deficient in some key nutrients. Knowing what doctor checks your vitamins and minerals is the first step toward correcting a potential imbalance and improving your overall health and well-being, which is a cornerstone of any effective nutrition diet.

Quick Summary

For vitamin and mineral level checks, your primary care doctor is the first stop. Based on blood test results and underlying causes, they may provide treatment or refer you to a specialist like a hematologist, endocrinologist, or gastroenterologist. A registered dietitian can also provide critical dietary guidance.

Key Points

Primary Care Physician: Your first and most crucial point of contact for initial screening and blood work.
Specialist Referrals: If initial tests are abnormal, a PCP can refer you to an endocrinologist, hematologist, or gastroenterologist for further investigation.
Registered Dietitian: This expert helps assess dietary causes and provides personalized meal plans to correct deficiencies naturally.
Diagnostic Testing: Blood tests are the standard method for measuring vitamin and mineral levels, with different specialists focusing on different aspects.
Holistic Approach: Integrative or functional medicine doctors can offer more comprehensive nutritional panels and a focus on root causes.
Avoid Self-Medicating: Consulting a professional is essential before starting supplements, as misuse can lead to toxicity.

Your First Point of Contact: The Primary Care Physician

When you suspect you might have a vitamin or mineral deficiency, the first professional you should consult is your primary care physician (PCP) or general practitioner (GP). Your PCP can order initial lab work, such as blood tests, to screen for the most common deficiencies. These standard screenings often include tests for:

Vitamin D: A very common deficiency, especially in regions with limited sunlight.
Vitamin B12: Essential for nerve function and red blood cell production; deficiencies are common in those on vegan diets or with malabsorption issues.
Iron: The test for iron levels is standard for diagnosing iron-deficiency anemia.
Folate (Vitamin B9): Often checked along with B12, as deficiencies can cause anemia.

Your PCP will evaluate your symptoms, medical history, and diet to determine if further testing or a referral to a specialist is necessary. They can provide initial guidance on dietary adjustments and prescribe supplements for more straightforward cases.

When Specialists Are Necessary

For more complex or persistent deficiencies, your PCP may refer you to a specialist. The type of specialist depends on the suspected root cause of the nutritional imbalance.

The Endocrinologist

If your deficiency is linked to a hormonal problem, an endocrinologist is the right specialist. They focus on the endocrine system, which includes the thyroid and other glands that regulate metabolism. For instance, a Vitamin D deficiency can be tied to a hormonal imbalance that affects calcium and phosphate regulation. Similarly, problems with the thyroid can affect levels of minerals like selenium and iodine.

The Hematologist

A hematologist specializes in blood disorders. If your blood test shows signs of anemia caused by deficiencies in Vitamin B12, folate, or iron, a hematologist can provide expert diagnosis and treatment. This is particularly important for conditions like pernicious anemia, an autoimmune disorder that affects B12 absorption.

The Gastroenterologist

If malabsorption is the suspected cause of a deficiency, a gastroenterologist, who specializes in the digestive system, is the best choice. Conditions like Crohn's disease, celiac disease, or inflammatory bowel disease can hinder the body's ability to absorb essential vitamins and minerals from food.

The Dermatologist

Skin, hair, and nail problems are often a sign of a vitamin or mineral deficiency. A dermatologist can help determine if issues like hair loss, brittle nails, or dry skin are caused by low levels of vitamins A, B7 (biotin), C, D, E, or minerals like iron or zinc.

Partnering with Dietitians and Nutritionists

While a doctor diagnoses and treats medical conditions related to deficiencies, a registered dietitian (RD) or nutritionist is the expert in the dietary aspect. A dietitian can conduct a thorough assessment of your eating habits and design a personalized meal plan rich in the nutrients you need. They provide invaluable guidance on:

Identifying Nutrient-Rich Foods: Pinpointing the specific dietary sources of the vitamins and minerals you are lacking.
Making Sustainable Changes: Helping you integrate healthier eating patterns into your daily life.
Supplementation Guidance: Offering advice on the type, dosage, and safety of nutritional supplements.

Functional and Integrative Medicine

For those seeking a more holistic approach, a functional or integrative medicine doctor might be an option. These practitioners often perform more comprehensive nutritional and metabolic testing than a conventional PCP. They focus on identifying the root causes of symptoms rather than just treating the symptoms themselves.

Choosing the Right Expert: A Comparison


Professional Role	When to Consult	What They Do	Common Tests & Treatments	Expertise
Primary Care Physician	First point of contact for any health concerns or initial deficiency suspicion.	Initial diagnosis, basic lab tests, general advice, and referrals.	Blood tests for common vitamins (D, B12, Iron, Folate) and some minerals.	Broad medical knowledge, initial health assessment, manages overall care.
Endocrinologist	Suspected hormonal or metabolic imbalance affecting nutrient levels.	Treats disorders of the endocrine system that regulate metabolism.	Specialized blood tests for specific hormones and related nutrient levels.	Hormonal health, metabolism, thyroid disorders.
Hematologist	Anemia caused by vitamin or mineral deficiency.	Diagnoses and treats disorders of the blood and bone marrow.	Comprehensive blood work, potentially including a bone marrow biopsy.	Blood disorders, anemia, clotting issues.
Gastroenterologist	Suspected malabsorption issues in the digestive tract.	Investigates and treats conditions affecting nutrient absorption.	Endoscopy, colonoscopy, specialized absorption tests.	Digestive health, malabsorption, gut disorders.
Registered Dietitian	Need help improving diet, assessing intake, or choosing supplements.	Provides dietary analysis, counseling, meal planning, and supplement advice.	Nutritional assessments, dietary planning, food journaling.	Diet and nutrition science.

Conclusion: Navigating Your Nutritional Journey

Your path to assessing and correcting vitamin and mineral deficiencies begins with an honest conversation with your primary care physician. They can initiate the necessary blood tests and determine whether a referral to a specialist is warranted based on your specific symptoms and medical history. Partnering with a registered dietitian is also highly recommended, as they can provide the essential dietary guidance needed to support your overall health and prevent future deficiencies. Always prioritize professional medical advice over self-medicating with supplements, as overuse can cause toxicity, especially with fat-soluble vitamins. Taking a proactive, team-based approach to your nutritional health is the best way to ensure your body gets the vital nutrients it needs to thrive.

For more in-depth information about vitamin and mineral intake, the NIH Office of Dietary Supplements is an excellent resource.

Frequently Asked Questions

Initial signs of a vitamin deficiency can be vague and may include fatigue, hair loss, brittle nails, skin issues, brain fog, and irritability.

No, a standard wellness check-up blood panel typically does not include a full nutritional screening. You will likely need to ask your doctor to order specific tests for particular vitamins or minerals you are concerned about.

You should see a specialist if your primary care doctor suspects an underlying cause for your deficiency, such as a hormonal imbalance (endocrinologist), a blood disorder (hematologist), or malabsorption issues (gastroenterologist).

While both can provide dietary guidance, a registered dietitian (RD) typically has more extensive, regulated education and training. RDs can work closely with your medical team to develop a precise, evidence-based meal plan.

The reliability of at-home vitamin tests varies, and they often lack the crucial medical interpretation needed to determine the correct course of treatment. A finger-prick sample might also be less accurate than a venous blood draw from a lab.

Supplements can help correct a deficiency, but they should only be used under a doctor's supervision. Taking supplements incorrectly or in excess can be harmful, especially with fat-soluble vitamins like A, D, E, and K.

Yes, deficiencies can occur despite a seemingly healthy diet. They can be caused by underlying medical conditions, such as malabsorption issues or autoimmune diseases like pernicious anemia.