Vitamin B12

Sources of Vitamin B12

Animal-Based Foods

Found predominantly in animal products like meat, fish, poultry, eggs, and dairy products.

Fortified Foods

Some plant-based milks, breakfast cereals, and nutritional yeasts are fortified with B12, crucial for vegetarians and vegans.

Dietary Supplements

B12 supplements are often recommended for those with dietary restrictions or absorption issues.

Functions of Vitamin B12

Red Blood Cell Formation: Essential for the production of healthy red blood cells, preventing anemia.

DNA Synthesis: Plays a role in DNA synthesis and repair.

Nervous System Health: Vital for the maintenance of the nervous system, including nerve cells and neurotransmitters.

Effects of Vitamin B12 Deficiency

Pernicious Anemia: A specific form of anemia due to B12 deficiency, characterized by fatigue, weakness, and cognitive disturbances.

Neurological Issues: Deficiency can lead to nerve damage, causing numbness, tingling in the hands and feet, and balance issues.

Psychological Symptoms: Includes depression, confusion, and memory problems.

Recommended Dietary Allowances (RDAs) for Vitamin B12

Adults

2.4 micrograms per day.

Pregnant Women

Increased needs, around 2.6 micrograms per day

Lactating Women

2.8 micrograms per day.

Properties of Vitamin B12

Chemical Structure

Contains a metal ion, cobalt – hence the term 'cobalamin'.

Stability

Relatively stable to heat and unaffected by cooking, but sensitive to light and strong acids or alkalis.

Water-Solubility

Easily dissolved in water, facilitating its transport and absorption in the body.

Example Exam Questions and Answers

1. What are the primary dietary sources of Vitamin B12?

Vitamin B12 is primarily found in animal-based foods like meat, fish, poultry, eggs, and dairy products, and is also available in fortified plant-based foods and dietary supplements.

2. Explain the role of Vitamin B12 in the body.

Vitamin B12 is essential for the formation of red blood cells, DNA synthesis and repair, and the maintenance of the nervous system.

3. What are the effects of Vitamin B12 deficiency?

Deficiency can lead to pernicious anemia, neurological issues such as nerve damage and balance problems, and psychological symptoms like depression and confusion.