Vitamin B12, or cobalamin, is essential for red blood cell production, DNA formation, and nervous system health. As the article warns, *“a lack of vitamin B12 can be a terrible health problem.”*

**Key Symptoms:**
Vitamin B12 deficiency can lead to various health issues including *“anemia, cardiovascular diseases, fatigue, depression, reduced vision, headaches, digestive problems, and tingling in limbs.”* Mood changes like nervousness and irritability may also occur.

**Causes of Deficiency:**
The deficiency arises when the body can’t absorb B12 or doesn’t get enough from food. Causes include:
• *“Diet low in vitamin B12”*
• *“Gastritis, which reduces stomach acid needed to absorb B12”*
• *“Pernicious anemia, a lack of intrinsic factor protein”*
• Digestive issues like Crohn’s or celiac disease
• *“Gastrointestinal surgery,”* such as gastric bypass
• *“Excessive alcohol consumption”*
• *“Genetic problem with vitamin B12 transport”*

**Top Food Sources:**
To prevent deficiency, eat B12-rich foods:
• *“Liver, seafood (especially cockles), salmon, tuna, ground beef, milk, yogurt, eggs,”* and
• *“Fortified foods and breakfast cereals.”*

**Conclusion:**
Vitamin B12 is vital for your energy, brain, and blood health. As the article highlights, maintaining adequate intake is key to avoiding serious health issues. Would you like a version formatted for a blog or social media?