Nutrition Basics: An Active Approach

Section 10.1: Blood’s Function in the Body and in Metabolism

• Blood Composition and Function

• Plasma: The liquid portion of blood, primarily composed of water.

  • Maintains fluid balance between blood and tissues
  • Helps to regulate blood pH and body temperature

• Red Blood Cells (RBCs): Transport oxygen from the lungs to tissues; most prevalent cells in blood.

• White Blood Cells (WBCs): Key components of the immune system, identifying and destroying foreign invaders.

  • Includes various types like neutrophils, basophils, and lymphocytes.

• Platelets: Cell fragments that play a crucial role in blood clotting when blood vessels are injured.

• Nutrient Transport

• Blood acts as a transportation medium for nutrients absorbed in the intestine to cells throughout the body.

• Oxygen absorbed by the lungs is transferred to the cells for metabolic processes.

• Kidneys filter excess water and eliminate carbon dioxide back to the lungs for exhalation.

• A healthy blood composition includes appropriate water levels and the correct concentration of nutrients (e.g., albumin, electrolytes).

• Health Implications

• Various blood tests can indicate health statuses such as nutrient deficiencies or diseases.

• Important blood biomarkers include:

  • Red Blood Cell Count: Indicates oxygen-carrying capacity.
  • Hematocrit and Hemoglobin Levels: Assess anemia risks.
  • White Blood Cell Count: Indicates infections.

• Key Takeaways

• Blood is vital for transporting nutrients and waste.

• The plasma contains numerous vital substances, including proteins, electrolytes, and hormones.

• Blood undergoes continuous renewal from bone marrow-derived stem cells to function optimally.

Section 10.2: Metabolism Overview

• Definitions

• Metabolism: Totality of biochemical reactions essential for cellular function - includes catabolism (breakdown of molecules) and anabolism (building larger molecules).

• Energy Metabolism: Pathways that manage energy storage and release.

• Stages of Nutrient Breakdown

• Stage 1: Glycolysis (for glucose) or β-oxidation (for fatty acids) occurs in the cytosol.

• Stage 2: Citric acid cycle (Krebs cycle) in the mitochondria.

• Stage 3: Electron transport chain and ATP synthesis, where energy is captured for cellular use.

• Anabolism

• Constructs new tissues (like muscles and bones) and stores energy as glycogen or fat.

• Gluconeogenesis: Process of converting non-carbohydrates, like amino acids, into glucose primarily in the liver.

• Key Takeaways

• Metabolic processes balance energy utilization and molecular construction to support cellular functions.

• When energy is abundant, anabolic processes dominate; during energy scarcity, catabolic pathways become prominent.

Section 10.3: Vitamins Important for Metabolism and Blood Function

• B Vitamins' Functions

• Vitamin B1 (Thiamine): Crucial for glucose metabolism and synthesis of nucleic acids (RNA/DNA). Deficiency leads to beriberi.

• Vitamin B2 (Riboflavin): Key for electron transport. Deficiency (ariboflavinosis) may cause skin issues and light sensitivity.

• Vitamin B3 (Niacin): Involved in macronutrient metabolism; deficiency causes pellagra (diarrhea, dermatitis, dementia).

• Vitamin B6 (Pyridoxine): Essential for amino acid metabolism and neurotransmitter synthesis; deficiency leads to weakness and confusion.

• Vitamin B9 (Folate): Important for DNA synthesis and cell growth; deficiency linked to macrocytic anemia and spina bifida.

• Vitamin B12 (Cobalamin): Necessary for red blood cell production; deficiency can lead to pernicious anemia.

• Vitamin K: Critical for blood clotting and bone metabolism; deficiency can cause bleeding issues.

• Key Takeaways

• B vitamins act as coenzymes vital for energy metabolism.

• Their deficiencies can have serious health impacts, especially during development.

Section 10.4: Minerals Important for Metabolism and Blood Function

• Essential Minerals

• Magnesium: Required as a cofactor for ATP synthesis; deficiency leads to muscle spasms and poor appetite.

• Iron: Crucial for hemoglobin function in oxygen transport; deficiency results in anemia with fatigue and pallor.

• Zinc: Involved in DNA/RNA synthesis; severe deficiency affects growth and immune function.

• Iodine: Necessary for thyroid hormone production; deficiency may cause goiter.

• Selenium, Copper, Manganese, Chromium: Various metabolic roles including antioxidant properties and enzyme functions.

• Key Takeaways

• Minerals are vital cofactors in numerous biochemical reactions but are not energy sources themselves.

• Iron and its bioavailability issues are critical in maintaining healthy blood function and metabolism.

Section 10.5: Iron Deficiency Anemia

• Signs and Symptoms

• Symptoms include fatigue, weakness, pale skin, and dizziness. Severe cases could lead to heart palpitations.

• Treatment Strategies

• Iron supplementation and dietary modifications (increase iron intake and vitamin C).

• Awareness of inhibitors of iron absorption (e.g., phytates and calcium).

• Key Takeaways

• Iron deficiency anemia poses significant health risks and is often linked to dietary inadequacies and infections.

• At-risk populations require targeted interventions to reduce prevalence and address long-term health impacts.