Who Is At Risk of B12 Deficiency?

Published:  12/05/2019

Suffering from fatigue or nerve issues? Learn why B12 is essential, common deficiency risks, and expert dosage guidelines for supplementation. 

Vitamin B12, also known as cobalamin, is an important water-soluble vitamin important for red blood cell production, brain health and DNA synthesis.

A deficiency in this key vitamin can cause serious symptoms, including fatigue, nerve damage, digestive issues and neurological problems like depression and memory loss.

While most people get enough B12 from a balanced diet, certain groups are more susceptible to deficiency:

Vegans and Vegetarians: B12 is primarily found in animal products (meat, poultry, fish, eggs, dairy). Plant-based diets require careful planning, often needing fortified foods or supplements, to ensure adequate intake.

Older Adults: As people age, their ability to absorb B12 from food can decrease due to reduced stomach acid and intrinsic factor production.

Individuals with Digestive Issues: Conditions like Crohn's disease, celiac disease, or those who have had weight loss surgery can impair B12 absorption.

People taking certain medications: Some medications, like metformin (for type 2 diabetes) and acid-blocking drugs, can interfere with B12 absorption.

Have alcohol use disorder: Too much alcohol can harm the digestive system and make it difficult to absorb vitamin B12.

Why B12 Is Important

Vitamin B12, also known as cobalamin, is a crucial nutrient that plays an essential role in numerous bodily functions. Here's why it's so important:

Red Blood Cell Formation and Anemia Prevention: B12 is vital for the production of healthy red blood cells. A deficiency can lead to megaloblastic anemia, where red blood cells are abnormally large and inefficient at carrying oxygen, resulting in fatigue, weakness, and other symptoms.

Nerve Function and Nervous System Health: It's critical for the development, myelination (formation of the protective sheath around nerves), and proper functioning of the central nervous system. This impacts everything from sensation and movement to cognitive processes.

DNA Synthesis: B12 is a key component in the creation and regulation of DNA, the genetic material found in all cells.

Cell Metabolism and Energy Production: It helps the body convert food (proteins, carbohydrates, and fats) into energy.

Cognitive Function and Mood: While research is ongoing, B12 deficiency has been linked to cognitive issues like memory loss, confusion, and even an increased risk of depression and dementia. Maintaining adequate levels may support brain health.

Fetal Development: During pregnancy, sufficient B12 is crucial for healthy fetal development, and a deficiency can increase the risk of birth defects.

Symptoms of B12 Deficiency Can Include:

• Fatigue and weakness
• Pale or yellowish skin
• Sore mouth or tongue
• Difficulty with balance
• Memory problems, confusion, or depression
• Vision problems
• Numbness or tingling in hands and feet

If you suspect a B12 deficiency, it's important to consult a healthcare professional for diagnosis and appropriate treatment, which may involve dietary changes, supplements, or injections.

Vitamin B12 Recommendations

This is the B12 Supplement I recommend for adults over 50 or vegans or vegetarians. You can order it from Amazon here. 

Here's a breakdown of common dosage recommendations:

1. General Recommended Dietary Allowance (RDA):

Adults (14+ years): 2.4 mcg per day
Pregnant individuals: 2.6 mcg per day
Breastfeeding individuals: 2.8 mcg per day
Children: Lower doses depending on age (e.g., 0.4 mcg for infants 0-6 months, up to 1.8 mcg for children 9-13 years).
These RDAs are for healthy individuals absorbing B12 efficiently from their diet.

2. For Specific Groups (Prevention/Maintenance):

Vegans and Vegetarians: Since B12 is primarily found in animal products, supplementation is essential for those on plant-based diets.

Daily: 25-100 mcg daily
Weekly: 1000-2000 mcg once a week
Fortified Foods: As discussed previously, aim for 3 servings of B12-fortified foods a day, each containing around 4.5 mcg (190% of the updated DV of 2.4 mcg). This provides approximately 13.5 mcg daily.
Rationale: Due to the limited absorption capacity via intrinsic factor, higher oral doses are often recommended to ensure sufficient absorption through passive diffusion.

Older Adults (over 50): As people age, the ability to absorb B12 from food can decrease due to reduced stomach acid and intrinsic factor. Many sources recommend 500-1000 mcg daily, even without a diagnosed deficiency, to ensure adequate absorption from supplements.  Rationale: B12 from supplements is not bound to food protein and therefore does not require stomach acid for its initial release, making it a more reliable source for older adults.

Individuals on certain medications (e.g., metformin, PPIs): These medications can interfere with B12 absorption. A doctor will typically recommend specific dosages based on the individual's needs and monitoring.

Possible Drug Interactions Include:

Possible interactions include:

• Aminosalicylic acid (Paser). Taking this drug used to treat digestive problems might reduce your body's ability to absorb vitamin B-12.
• Colchicine (Colcrys, Mitigare, Gloperba). Taking this anti-inflammatory drug used to prevent and treat gout attacks might decrease your body's ability to absorb vitamin B-12.
• Metformin (Glumetza, Fortamet, others). Taking this diabetes drug might reduce your body's ability to absorb vitamin B-12.
• Proton pump inhibitors. Taking omeprazole (Prilosec), lansoprazole (Prevacid) or other stomach acid-reducing drugs might decrease your body's ability to absorb vitamin B-12.
• Vitamin C (ascorbic acid) supplements. Taking vitamin B-12 with vitamin C might reduce the available amount of vitamin B-12 in your body. To avoid this interaction, take vitamin C two or more hours after taking a vitamin B-12 supplement.