In the quest for a healthy and balanced diet, vitamins play a fundamental role. Among all of them, vitamin B12 (also known as cobalamin) stands out for its critical importance in vital functions of the organism. Unlike other vitamins, B12 is not produced by the human body, so we must obtain it exclusively through food.
"Vitamin B12 is not just a nutrient, it's a fundamental pillar for your nervous system, your brain and your daily energy." - Optimal Nutrition Principle
What is Vitamin B12 and What is it Used For?
Vitamin B12 or cobalamin is a water-soluble vitamin from the B complex that performs essential functions in the organism:
Main Functions of Vitamin B12
- Development and maintenance of the nervous system: Protects neurons and maintains myelin integrity (nerve covering)
- Optimal brain function: Improves memory, concentration and cognitive function
- Hemoglobin formation: Essential for producing red blood cells and preventing anemia
- DNA synthesis: Participates in cellular replication and tissue growth
- Energy metabolism: Converts food into usable energy
- Healing and regeneration: Accelerates tissue repair and muscle recovery
The "Energy Vitamin"
In the world of fitness and personal training, vitamin B12 is informally known as the "energy vitamin". This is due to its crucial role in:
- Fat metabolism: Helps burn calories efficiently
- Carbohydrate metabolism: Converts sugars into energy
- Protein synthesis: Fundamental for muscle growth and maintenance
- Toxin elimination: Contributes to body detoxification
Vitamin B12 is stored mainly in the liver, and the organism uses it according to its needs. This means the body can maintain reserves for several years, but also makes deficiencies difficult to detect until advanced stages.
Foods Rich in Vitamin B12
A unique characteristic of vitamin B12 is that it is only found in animal-based foods. Plant foods do not provide cobalamin naturally, making it especially important for people following a personalized diet vegetarian or vegan to consider supplementation.
Cheese and Dairy Products: The Richest Source
Dairy products are the easiest way to reach the recommended daily amount of vitamin B12:
Cheeses with highest B12 content:
- Swiss cheese: 3.34 μg per 100g (139% RDA)
- Parmesan cheese: 1.4 μg per 100g (58% RDA)
- Mozzarella: 2.28 μg per 100g (95% RDA)
- Cheddar cheese: 0.83 μg per 100g (35% RDA)
Other dairy:
- Whole milk: 0.5 μg per glass
- Natural yogurt: 0.6-1.2 μg per serving
- Cottage cheese: 0.43 μg per 100g
"A simple piece of Swiss cheese at breakfast can cover more than 100% of your daily B12 needs." - Nutritional Advice
Meat: Nutritional Powerhouse
Red meat and organs are exceptional sources of vitamin B12:
#### Organs (the richest)
- Beef liver: 60-80 μg per 100g (¡3333% RDA!)
- Lamb liver: 85 μg per 100g
- Turkey liver: 47 μg per 100g
- Lamb kidneys: 55 μg per 100g
#### Muscle meats
- Lamb meat: 2.6 μg per 100g (108% RDA)
- Beef (sirloin): 2.4 μg per 100g (100% RDA)
- Veal: 2.0 μg per 100g (83% RDA)
- Pork: 0.7 μg per 100g (29% RDA)
Important tip: If you train at our gym and seek to improve your performance, beef not only provides B12, but also iron, zinc and high biological value proteins, essential for muscle development.
Ethical recommendation: Whenever possible, opt for meats from free-range animals with natural feed. It's not only healthier, but also promotes sustainable practices.
Fish and Seafood: Omega-3 + B12
Seafood products are an exceptional option because they combine vitamin B12 with Omega-3 fatty acids and high-quality proteins:
#### Fish
- Mackerel: 19 μg per 100g (792% RDA) - The richest source!
- Wild salmon: 4.8 μg per 100g (200% RDA)
- Tuna: 10.9 μg per 100g (454% RDA)
- Canned sardines: 8.9 μg per 100g (371% RDA)
- Trout: 7.5 μg per 100g (312% RDA)
#### Shellfish
- Clams: 98 μg per 100g (¡4083% RDA!)
- Mussels: 24 μg per 100g (1000% RDA)
- Octopus: 36 μg per 100g (1500% RDA)
- Fun fact: 50g of raw octopus provides 150% RDA, and cooking doubles it
- Crab: 10 μg per 100g (417% RDA)
- Lobster: 4 μg per 100g (167% RDA)
- Oysters: 16 μg per 100g (667% RDA)
Eggs: The Versatile Superfood
Eggs are a complete and economical source:
- Whole egg: 1.1 μg per unit (46% RDA)
- The highest concentration is in the yolk: 2 μg per yolk
- Egg white: Barely contains B12
Important: Don't eliminate yolks if you want to optimize your B12 intake. Yolks also provide fat-soluble vitamins (A, D, E, K) and choline, essential for brain function.
Cod Liver Oil
A very potent traditional supplement:
- 1 tablespoon (15ml): 1.36 μg (57% RDA)
- Also provides vitamin A and D
Fortified Foods (for vegans/vegetarians)
If you follow a plant-based diet, these fortified foods can help:
- Fortified plant milks (soy, almond, oat): 0.4-1.2 μg per glass
- Fortified cereals: 1.5-6 μg per serving
- Nutritional yeast: 2.4 μg per tablespoon
- Fortified soy products: Variable
Important note: B12 absorption from fortified plant sources is lower than from animal sources. If you're vegan, consider consulting a professional about personalized supplementation.
Vitamin B12 Deficiency: Symptoms and Risks
Vitamin B12 deficiency is more common than thought, especially in:
- People over 50 years (reduced absorption capacity)
- Strict vegetarians and vegans
- People with digestive problems (Crohn's, celiac, gastritis)
- People with previous gastric surgery
- Alcoholics
- People taking certain medications (metformin, antacids)
Symptoms of B12 Deficiency
#### Initial symptoms
- Extreme fatigue and constant weakness
- Lack of energy for daily activities
- Loss of appetite and involuntary weight loss
- Pallor (anemia)
#### Neurological symptoms (more serious)
- Tingling and numbness in hands and feet
- Balance problems and coordination
- Memory loss and cognitive difficulties
- Mental confusion and disorientation
- Mood changes: depression, irritability
- Dementia (in severe and prolonged cases)
#### Additional physical symptoms
- Megaloblastic anemia: large and dysfunctional red blood cells
- Glossitis: inflamed, red and painful tongue
- Mouth ulcers
- Blurred vision
- Difficulty breathing
- Dizziness
Consequences of Prolonged Deficiency
Nervous system:
- Irreversible nerve damage if not treated in time
- Permanent peripheral neuropathy
- Spinal cord degeneration
Cardiovascular system:
- Increased homocysteine (cardiovascular risk factor)
- Greater risk of heart attacks and strokes
Mental health:
- Clinical depression
- Psychosis
- Irreversible dementia
Pregnancy:
- Neural tube defects in fetus
- Premature birth
- Low birth weight
"Vitamin B12 is not optional for your brain. Prolonged deficiency can cause irreversible neurological damage." - Medical Warning
Excess Vitamin B12: Is it Possible?
Good news: No upper toxicity limit has been established for vitamin B12. This means:
- No studies demonstrate adverse effects from excess B12
- The body excretes excess through urine
- You can consume high doses without apparent risk
Why is it so Safe?
- Water solubility: Dissolves in water and doesn't accumulate like fat-soluble vitamins
- Efficient excretion: Kidneys eliminate excess
- Low absorption at high doses: Body absorbs less when there's excess
Situations of Elevated Levels
Very high B12 levels in blood may indicate:
- Recent supplementation (normal and benign)
- Liver diseases
- Certain types of leukemia
- Polycythemia vera
Important: If your tests show very high B12 without supplementation, consult a doctor to rule out pathologies.
Recommended Daily Amounts (RDA)
By age:
- 0-6 months: 0.4 μg
- 7-12 months: 0.5 μg
- 1-3 years: 0.9 μg
- 4-8 years: 1.2 μg
- 9-13 years: 1.8 μg
- 14+ years: 2.4 μg
- Pregnant: 2.6 μg
- Lactating: 2.8 μg
Athletes and active people: May benefit from higher doses (5-10 μg daily) due to greater metabolic wear during intense training.
Vitamin B12 and Sports Performance
For those who train regularly, vitamin B12 is especially important:
Benefits for Athletes
- Increased energy production: Improves carbohydrate and fat metabolism
- Muscle recovery: Facilitates protein synthesis
- Reduced fatigue: Prevents anemia and increases oxygen transport
- Better neuromuscular function: Optimizes brain-muscle connection
- Strengthened immune system: Fewer interruptions from illness
Deficiency Symptoms in Athletes
- Unexplained performance decrease
- Excessive post-training fatigue
- Slow recovery
- Loss of strength and muscle mass
- Frequent cramps
Vitamin B12 Supplementation
Who Needs Supplements?
Mandatory for:
- Strict vegans and vegetarians
- People over 50 years
- People with digestive problems
- Pregnant and lactating vegans
Recommended for:
- High-performance athletes
- People with low animal product diet
- People with deficiency symptoms
Forms of Supplementation
- Cyanocobalamin: More stable and economical synthetic form
- Methylcobalamin: Active form, better absorption
- Hydroxocobalamin: Longer retention
- Adenosylcobalamin: Active mitochondrial form
Supplementation Doses
Preventive: 10-25 μg daily
Therapeutic (mild deficit): 250-500 μg daily
Severe deficit: 1000-2000 μg daily (under medical supervision)
Injections: 1000 μg weekly/monthly (severe cases)
Vitamin B12 Analysis
When to Get Tested?
- Annually if you're vegan/vegetarian
- If you experience deficiency symptoms
- Over 50 years (every 1-2 years)
- If you take medications affecting absorption
Reference Values
- Normal: 200-900 pg/mL
- Optimal for athletes: >500 pg/mL
- Deficiency: \<200 pg/mL
- Severe deficiency: \<150 pg/mL
Note: Some experts consider values \<400 pg/mL may already cause symptoms in sensitive people.
Frequently Asked Questions about Vitamin B12
Can I Get B12 from Plant Sources?
Not naturally in significant amounts. The only plant products with B12 are artificially fortified. Algae and non-fermented yeasts contain B12 analogs that the body cannot use.
Does Cooking Destroy Vitamin B12?
B12 is relatively heat stable, but:
- Boiling: 30-40% loss
- Frying/roasting: 20-30% loss
- Microwave: Minimal loss (10-15%)
Tip: Steam or bake at moderate temperatures to preserve more B12.
Do Probiotics Produce B12?
Some intestinal bacteria produce B12, but it's synthesized in the colon, after the absorption point (small intestine). Therefore, we cannot use this endogenous B12.
How Long Does it Take to Correct a Deficiency?
- Anemia symptoms: 2-4 weeks improvement
- Neurological symptoms: 3-6 months (may be irreversible if damage is severe)
- Reserve normalization: 6-12 months
Conclusion: Your Invisible Ally for Health and Performance
Vitamin B12 is much more than a simple nutrient: it's an essential regulator of your nervous system, your energy and your physical and mental performance.
Key Points to Remember:
- ✅ Only in animal foods: Dairy, meat, fish, eggs
- ✅ Critical for vegans: Supplementation is not optional
- ✅ Important for athletes: Optimizes energy and recovery
- ✅ Safe at high doses: No known toxicity
- ✅ Monitor your levels: Especially if you have risk factors
- ✅ Act quickly on deficit: Neurological damage can be irreversible
"Your brain, your energy and your muscles depend on vitamin B12. It's non-negotiable in a healthy diet." - Integral Nutrition Philosophy
If you have questions about your vitamin B12 intake or need help designing a balanced and personalized diet that covers all your nutritional needs, don't hesitate to request a private consultation. Your health and performance will thank you.
Your body needs B12 to function. Give it what it needs: quality foods, conscious monitoring and supplementation when necessary.