Vitamins & minerals
Vitamins & Minerals
Course Code: NUSC 4250
Subject: Nutrition for Exercise & Sport
Outline of Topics Covered
Classifying vitamins and minerals
Micronutrients as building blocks
Micronutrients as antioxidants
Micronutrients as energy producers
Micronutrient recommendations
Classification of Vitamins
Fat Soluble Vitamins
Characteristics:
Excess stored in fat tissues and liver.
Toxicity can occur due to accumulation.
List:
Vitamin A
Vitamin D
Vitamin E
Vitamin K
Water Soluble Vitamins
Characteristics:
Excess is secreted through urine.
Most involved in energy metabolism.
List:
B-Complex Vitamins (e.g., B1, B2, B3, etc.)
Vitamin C
Classification of Minerals
Major Minerals:
List:
Calcium *
Phosphorous
Magnesium
Sodium
Potassium
Iron *
Zinc
Fluoride
Iodine
Trace Minerals:
Required in smaller amounts compared to major minerals.
Micronutrients as Building Blocks
Essential for various bodily functions, particularly for:
Bone health (Calcium, Phosphorous, Vitamin D)
Immune function (Vitamin C, Vitamin D)
Dental health (Fluoride)
Vitamin D Overview
Unique Characteristics:
Can be synthesized by the body when exposed to sunlight.
Obtained from certain foods.
Functions of Vitamin D
Physiological Roles:
Maintains blood calcium and phosphorus levels.
Strengthens bones.
Supports immune function.
Types of Vitamin D
Vitamin D2 (Ergocalciferol):
Found in plant sources and some supplements.
Vitamin D3 (Cholecalciferol):
Found in animal foods and synthesized by the body.
Vitamin D Activation Process
Step 1: Conversion of 7-dehydrocholesterol in skin to previtamin D3 through ultraviolet light exposure.
Step 2: Conversion of previtamin D3 to vitamin D3 (cholecalciferol) in skin.
Further Activation:
Step 1: In the liver, cholecalciferol is converted to 25-hydroxy vitamin D (calcidiol).
Step 2: In the kidneys, it is converted to 1,25 dihydroxy vitamin D (calcitriol).
Assessing Vitamin D Status
Serum Levels of 25(OH)D:
<12 nmol/L: Severely deficient
12-<30 nmol/L: Deficient
30-50 nmol/L: Inadequate
>50 nmol/L: Adequate
>100-250 nmol/L: Suggested optimal (Zittermann, 2003)
>120-225 nmol/L: Suggested optimal (Heaney, 2011)
Virginia D Characteristics Table
Example dataset showcasing various vitamin D levels across different conditions and time points, including average serum levels and binding protein concentrations.
Relevant p-values implying statistical significance in the findings.
Factors Affecting Vitamin D Status
Influences:
Obesity
Skin tone
Sun exposure
Dietary intake
Implications of Suboptimal Vitamin D
Health consequences include:
Inflammation
High oxidative stress
Mitochondrial dysfunction
Muscle atrophy
Increased risk of depression and skeletal muscle weakness
Decreased mitochondrial biogenesis
Improving Vitamin D Status
Recommendations include:
Adequate sunlight exposure from April to late September in CT.
Increased consumption of food sources rich in Vitamin D.
Supplementation with D3 as needed.
Vitamin D Supplementation Regimens
Overview of recommended vitamin D supplementation based on serum status (Insufficient, Sufficient, Optimal).
Variations in supplementation doses and follow-up concentrations were discussed.
Calcium Overview
Significance:
Most abundant mineral in the body (1-2% of body weight).
99% of calcium stored in bones and teeth.
Essential for bone rigidity alongside phosphorus.
Regulation of Osteoblasts and Osteoclasts
Bone Remodeling Process:
Resting surface with active osteoblasts involved in bone formation.
Active osteoclasts resorb bone, important during injury and recovery.
Role of Exercise in Bone Health
Benefits of Weight-Bearing Exercises:
Activities like jumping, gymnastics, soccer, and resistance training improve bone health and might enhance performance.
Regulatory Functions of Calcium
Involved in:
Muscle contraction
Nerve transmission
Blood pressure regulation
Dietary Sources of Calcium
Common Sources:
Milk (300 mg/cup)
Sardines (200 mg/½ can)
Yogurt (330 mg/¾ cup)
Brick cheese (250 mg/3 cm cube)
Leafy greens, legumes, and fortified foods list with respective calcium contents.
Vitamin C in Collagen Synthesis
Role:
Co-factor essential for the hydroxylation of proline and lysine required for collagen synthesis.
Micronutrients as Antioxidants
Important vitamins include:
Vitamin A
Vitamin C
Vitamin E
Free Radicals Explained
Definition:
Molecules unstable due to the absence of an electron, creating a reactive property, produced during metabolic processes and external sources.
Consequences of Free Radical Damage
Potential impacts include:
Protein damage leading to altered enzyme activity and nutrient transport.
DNA damage which may result in mutations.
Lipid peroxidation affecting cell membranes.
Antioxidants Functionality
Mechanism:
Donate electrons to neutralize free radicals; utilize both endogenous and exogenous sources.
Endogenous Antioxidants
Increased levels following endurance exercise. Examples include:
Superoxide dismutase (SOD)
Glutathione peroxidase (GPX)
Catalase (CAT)
Exogenous Antioxidants
Derived from dietary sources, primarily fruits and vegetables, Vitamins A, C, and E.
Macrominerals and Microminerals
Discussions of their roles as energy contributors in exercise:
Iron
B-Vitamins (Thiamin, Riboflavin, Niacin, etc.)
Functions of B-Complex Vitamins in Exercise
Play primary roles in:
Energy metabolism
Protein metabolism
Red blood cell production
Coenzymes derived from B-Complex vitamins
Detailed lists with corresponding vitamin transformations for energy metabolism pathways (e.g., Glycolysis, Krebs cycle, etc.).
Red Blood Cell Production and Impact of Deficiency
Understanding the relationship between B6 deficiency and its effects on hemoglobin production and overall oxygen availability in the body.
Vitamin B9 (Folate) Importance
Especially significant for women of childbearing age for fetal tissue development and growth.
Primary Sources of B12
Predominantly found in animal products; highlighted need for supplementation in plant-based diets.
Deficiency and Performance Considerations of B-Complex Vitamins
Impact of deficiency on performance highlighted alongside supplementation benefits under adequate status.
Iron's Role in Energy Production
Essential for oxygen delivery and energy production via oxidative phosphorylation mechanisms.
Average Iron Stores in Population
Adult Men: 1,000 mg; Adult Women: 300-500 mg, Young Women: <200 mg, with notes on children's stores being virtually absent.
Monitoring Iron Levels and Deficiency Effects
Mechanisms of determining iron status including ferritin and transferrin saturation levels to identify deficiency and inflammation.
Symptoms of Iron Deficiency
Multifaceted impact ranging from fatigue to impaired physical performance and potential developmental anomalies in children.
Managing Iron Status
Strategies for increasing iron intake through heme and non-heme food sources, supplemented with Vitamin C for better absorption.
Micronutrient Recommendations for Exams
Summary of key recommended dietary intakes (RDI) of essential vitamins and minerals for performance and health benefits.
Micronutrient Status Assessment
Overview of dietary factors affecting nutrient status including recommendations for biochemical assessments to gauge deficiency risk.
Application of Micronutrient Knowledge
Overall, achieving recommended vitamin and mineral intakes is crucial for improving athletic performance compared to deficiency states. However, exceeding recommended amounts does not necessarily confer additional performance benefits.