Water Soluble Vitamins and Fat Soluble Vitamins

Water Soluble Vitamins and Fat Soluble Vitamins

Introduction

• Course: Nutrition 120.3

• Date: Tuesday March 24th, 2025

• Overview of the distinction between water-soluble and fat-soluble vitamins.

Land Acknowledgement

• Mention of participation by more than 150 USask staff, faculty, and students in the Blanket Project.

• Photo credit: Amaranta Sokol Como.

Learning Objectives

• Differentiate between water-soluble and fat-soluble vitamins.

• Understand the importance of water-soluble vitamins in the prevention and treatment of deficiencies.

Folate Fortification and Cancer (FYI ONLY)

• Studies show an increase in colon cancer since folate fortification began in 1998.

• Folate may stimulate DNA synthesis, promoting growth of pre-existing cancer cells.

• Systematic review and meta-analysis suggest high folate intake may protect against colon cancer, particularly with middle to high alcohol consumption.

Outline for Today

• B6: Pyridoxine Phosphate

• Vitamin B12

• Vitamin C

• Vitamins A, D, E, K (ADEK)

Vitamin B6 (Pyridoxal Phosphate)

• Sources: Found in chicken, fish, liver, and whole grains.

• Functions:
    - Co-enzyme needed for over 100 enzymes involved in carbohydrate, fat, and protein metabolism.
    - Key role in transamination and deamination reactions of proteins.
    - Essential for hemoglobin synthesis, critical for oxygen transport in red blood cells.
    - Supports production of white blood cells.

• Connection: Both Vitamin B6 and B12 are necessary for the formation of the myelin sheath essential for normal nerve transmission.

Vitamin B6 Deficiency

• Symptoms of Deficiency:
    - Neurological issues
    - Anemia due to impaired hemoglobin synthesis
    - Poor immune function
    - Elevated homocysteine levels, increasing risk for heart disease.

Vitamin B12

• Absorption:
    - Vital for proper iron absorption in the body.

• Sources: Exclusively found in animal products.

• Consideration: Vegans require supplementation of readily-absorbable B12 forms.

Pernicious Anemia

• Definition: A specific form of anemia associated with Vitamin B12 deficiency.

• Characterized by unresponsiveness to iron supplementation.

• Health Canada Regulation: Mandatory fortification of infant formula, simulated meat, egg products, and meal replacement products with Vitamin B12.

Vitamin B12 Absorption Pathway

1. Vitamin B12 in food is bound to protein.

2. Stomach acid and pepsin release vitamin B12 from proteins.

3. Cells in the stomach lining secrete intrinsic factor (IF).

4. In the duodenum, intrinsic factor binds to vitamin B12.

5. The complex (vitamin B12-intrinsic factor) binds to receptors in the ileum, facilitating absorption.

6. Microorganisms in the colon synthesize vitamin B12, which cannot be absorbed.

Factors Affecting Vitamin B12 Absorption

• A small amount can be absorbed through passive diffusion when intrinsic factor is absent.

• Low stomach acid and inadequate pancreatic secretions reduce absorption efficiency.

Importance of Vitamin B12

• Maintains myelin, insulating nerves and is essential for normal nerve conduction.

Consequences of Vitamin B12 Deficiency

• Decreased vitamin B12 → Increased folate deficiency → Elevated homocysteine levels.

• Symptoms include:
    - Increased risk of heart disease, stroke, and blood clots.
    - Poor growth and developmental issues.
    - Anemia, diarrhea, and nerve function problems.

Vitamin C

• Also known as ascorbic acid or ascorbate.

• Functions:
    - Antioxidant activity
    - Maintains immune system integrity
    - Essential for collagen production
    - Aids in absorption of non-heme iron (from plant sources).

Vitamin C Deficiency: Scurvy

• Historical context: Described by Ancient Greeks, Egyptians, and Romans.

• Key sources include fresh fruits and vegetables.

• Notable cases of scurvy occurred with armies and explorers lacking vitamin C access.

Symptoms of Scurvy

• Symptoms of deficiency when below 10 mg/day include:
    - Bleeding gums
    - Easy bruising
    - Weakened blood vessels due to faulty connective tissue.

Antioxidant Function of Vitamin C

• Acts against oxidative damage caused by reactive oxygen species (free radicals), which can lead to cellular damage.

Vitamin C Functions

• Operates as a co-enzyme in the synthesis of neurotransmitters, hormones, and collagen, essential for connective tissue structure.

Dietary Sources of Vitamin C

• Key food sources include:
    - Orange juice (250 ml), Kiwi (2), Apple (1), Strawberries (250 ml), Cantaloupe (250 ml), potatoes (1), Tomato (125 ml), Corn (125 ml), Broccoli (125 ml), Spinach (250 ml), Oatmeal (250 ml), Brown rice (250 ml), Whole wheat bread (2 slices), 2% Milk (250 ml), Cheddar cheese (50g), Sunflower seeds (60 ml), Walnuts (60 ml), Lentils (250 ml).

Recommendation for Vitamin C Intake

• Regular supplementation during colds can reduce illness duration.

• Encourage consumption of fruits and fluids during illness for recovery (e.g., chicken soup).

Key Takeaways on Vitamins B and C

• Strive for daily intake of varied diets; no single food provides all required nutrients.

• Fruits, vegetables, and grains are good sources of B vitamins.

• Meat and fish are excellent sources of B vitamins, while citrus fruits are rich in Vitamin C.

Fat Soluble Vitamins

• Overview: Include Vitamins A, D, E, and K (ADEK).

• Require bile and dietary fat for absorption.

• Transported through the lymphatic system via chylomicrons.

• Stored in the body for later use, leading to rare deficiencies but increased toxicity risk with high intake.

Vitamin A

• Sources:
    - Animal products (preformed: retinoids - retinol, retinal, retinoic acid) and plant sources (provitamin: carotenoids).

• Functions: Night vision, structural specialization of cells, and anti-infective properties.

• Plant sources include: orange foods such as mangoes, apricots, and carrots; animal sources including liver, fish, egg yolks, and milk.

Dietary Sources of Vitamin A

RDA for Vitamin A (RDA in μg)

Forms of Vitamin A

• Retinol (travels in the blood), Retinal (important for vision), Retinoic Acid (involved in cellular structure and differentiation).

• Carotenoids act as antioxidants when not utilized by the body.

Absorption of Vitamin A

• Preformed Vitamin A and carotenoids must be released from food proteins by pepsin.

• Enter mucosal cells in the intestine through diffusion, with 70%-90% absorption efficiency for preformed vitamin A.

• In mucosal cells, carotenoids can convert to retinoids.

Vitamin A in the Body

• Transported via chylomicrons to lymph; lipoproteins deliver to various tissues including red blood cells and muscle.

• Some carotenoids convert to retinol.

Vitamin A Deficiency Risks

• Vitamin A deficiency threatens health and sight, particularly in children, leading to symptoms such as_: poor appetite, anemia, increased infections, and higher childhood mortality.

• Associated Diseases: Measles and increased risk of death due to deficiency.

Vitamin A Toxicity

• Can occur from excessive intake, especially in those with liver disease.

• Medications like Retin A and Accutane can result in significant side effects.

Comparison of Vitamin A in Common Foods

• Example: Pepperoni pizza has high Vitamin A content (358 μg) compared to other fast foods.

Vitamin D Sources and Importance

• Sources include cheese, margarine, butter, fortified milk, and fatty fish.

• The body synthesizes Vitamin D through UV light exposure.

• Many individuals are Vitamin D deficient; fortified milk will have increased Vitamin D content starting December 31, 2025.

Importance of Vitamin D

• Regulates blood levels of calcium and phosphorus, critical for muscle contraction and bone health.

Vitamin D Toxicity

• Excessive Vitamin D can cause elevated calcium levels in the blood, leading to complications.

Vitamin D Deficiency in Adults and Children

• In adults: Osteomalacia, characterized by bone pain and fractures.

• In children: Rickets with bone deformities if calcium and phosphorus levels are insufficient, which can result in shorter statures.

Dietary Reference Intake for Vitamin D (IU and mcg/day)

Food Sources of Vitamin D

• Include specific quantities of foods like egg (2 large), beef liver (2 oz), salmon (90 g), chicken (90 g), and oils such as safflower and olive oil.

Quote of the Day

• "Much to learn you still have." - Yoda