Boosting Your Energy: A Functional Medicine Approach to Vitamin B12 Deficiency

Posted on May 5, 2025

Do you find yourself constantly tired, even after a full night’s sleep? Are you experiencing brain fog, tingling in your extremities, or mood changes that you can’t explain? If so, you might be among the millions of people suffering from vitamin B12 deficiency.

The Silent Epidemic

Vitamin B12 deficiency is surprisingly common yet often goes undiagnosed. It affects approximately 6% of people under 60, with this number jumping to a concerning 20% in those over 60 years old. Many more people have B12 that is not optimal but not below the official deficiency numbers.

Why B12 Is Your Body’s Best Friend

Before diving into treatments, let’s understand why B12 is so crucial for your wellbeing:

Vitamin B12 is a water-soluble vitamin containing cobalt in its structure (hence the name “cobalamin”). It comes in different forms, but methylcobalamin and 5-deoxyadenosylcobalamin are the two metabolically active forms your body actually uses.

Your body relies on B12 for several vital functions:

• Nervous system health: B12 helps form and maintain myelin, the protective sheath around your nerves that allows proper signal transmission.
• DNA synthesis and cell reproduction: B12 plays a key role in DNA synthesis and repair. Without enough B12, your cells can’t divide properly, which can lead to genomic instability.
• Red blood cell formation: B12 is necessary for creating healthy red blood cells. Without it, you may develop fewer, abnormally large blood cells (megaloblastic anemia).
• Energy production: B12 is involved in converting food into energy your body can use.

Signs You Might Be B12 Deficient

How do you know if you’re running low on this crucial vitamin? Look out for these common symptoms:

Physical symptoms can include:

• Persistent fatigue
• Cold hands and feet
• Pale skin
• Shortness of breath
• Heart palpitations
• Dizziness
• Headaches

Neurological and psychological symptoms may include:

• Numbness and tingling in hands and feet
• Difficulty walking
• Confusion
• Depression or anxiety
• Memory problems

GI issues can also appear:

• Inflammation of the tongue
• Loss of appetite
• Changes in bowel movements

Who’s at Risk?

Certain people have a higher chance of developing B12 deficiency:

• Vegans and vegetarians: Plant-based foods generally don’t contain B12 naturally.
• Adults over 65: Older adults are at higher risk and may need routine screening.
• People with digestive disorders: Conditions like celiac disease, Crohn’s disease, and small intestinal bacterial overgrowth can impair B12 absorption.
• Those who’ve had gastrointestinal surgery: Surgical procedures like gastric bypass can reduce your ability to absorb B12.
• Individuals with autoimmune conditions: Pernicious anemia, an autoimmune condition, attacks cells that produce intrinsic factor, which is necessary for B12 absorption.
• People taking certain medications: Some medications can deplete B12 levels, including proton pump inhibitors, oral contraceptives, and metformin (a common diabetes medication).

The Functional Medicine Approach to Treatment

Unlike conventional medicine that might simply prescribe a standard supplement, functional medicine looks at the whole person, identifying and addressing the root cause of your B12 deficiency. Here’s how a functional medicine practitioner might approach your treatment:

1. Comprehensive Testing

Initial testing typically includes a complete blood count to check for anemia and serum vitamin B12 levels. A level below 150 pg/mL is considered deficient.

For more accurate assessment, especially if your B12 levels are borderline, additional biomarkers may be tested:

• Homocysteine (levels above 12-15 micromol/L suggest deficiency)
• Methylmalonic acid (levels above 0.271 micromol/L suggest deficiency)

2. Personalized Supplementation

Based on the severity of your deficiency and its underlying cause, your practitioner might recommend:

For severe deficiency or neurological symptoms: Intramuscular injections are often the go-to for rapid repletion, especially in severe cases with neurological symptoms. These are typically given weekly until the deficiency is corrected, then monthly for maintenance.

The British National Formulary recommends that individuals with B12 deficiency due to malabsorption receive 1000 µg intramuscular hydroxocobalamin once every two months after the initial loading phase.

For patients with inflammatory bowel disease, the American Gastroenterological Association suggests 1000 µg of vitamin B12 injections at 1- to 4-week intervals for life.

For mild to moderate deficiency: High-dose oral supplements (500 to 1000 μg daily) can be effective even for people with absorption issues, as some B12 can be absorbed passively without intrinsic factor.

Studies show that high-dose oral B12 (1000 μg daily) can normalize serum levels and improve symptoms even in patients with pernicious anemia and other gastrointestinal disorders. This approach is more convenient and cost-effective than injections.

Alternative delivery methods: Nasal administration (like Nascobal) offers another option, particularly for maintenance therapy. The typical dosage is one 500 μg spray in one nostril weekly.

3. Dietary Modifications

A functional medicine practitioner will help you incorporate more B12-rich foods into your diet:

• For omnivores: Organ meats (especially liver), shellfish, fish, eggs, and dairy products
• For vegetarians: Dairy products, eggs, and B12-fortified foods
• For vegans: Nutritional yeast, fortified plant milks, cereals, and supplements

4. Addressing Root Causes

Beyond supplementation, functional medicine practitioners work to identify and treat underlying issues:

• Healing gut inflammation that may be preventing proper absorption
• Adjusting medications that might be depleting B12 levels
• Supporting stomach acid production if it’s low
• Addressing autoimmune conditions that might be causing malabsorption

The Results You Can Expect

With proper treatment, many people notice significant improvements:

• Increased energy levels within days to weeks
• Improved mood and mental clarity
• Relief from neurological symptoms like tingling and numbness
• Better exercise tolerance and recovery
• Enhanced immune function
• Improved sleep quality

Remember that recovery time varies depending on the severity and duration of your deficiency. Neurological symptoms may take longer to resolve, and in some cases of prolonged deficiency, certain effects may be permanent.

Prevention Is Better Than Cure

To prevent B12 deficiency, focus on consuming the recommended daily allowance through diet or supplements. Regular screening is warranted for those with risk factors to catch deficiency early.

If you’re experiencing persistent fatigue or any of the symptoms mentioned above, don’t dismiss them as “just getting older” or “being too busy.” Talk to a healthcare provider who understands functional medicine approaches to B12 deficiency. With proper diagnosis and treatment, you could be on your way to reclaiming your energy and vitality.

This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen.