Human Growth, Development, and Nutrition Across the Lifespan
Core concepts
Trace nutrient needs across the life cycle. Infancy: exclusive breastfeeding or formula for about the first six months, introduction of complementary foods around six months, iron and zinc as key concerns, and vitamin D supplementation for breastfed infants. Childhood: growth spurts, appetite variability, and the role of family feeding practices. Adolescence: peak calcium and iron needs, especially for menstruating adolescents. Pregnancy: increased needs for folate (neural tube defects), iron, iodine, and adequate but not excessive energy; avoid alcohol and high-mercury fish. Lactation: increased energy and fluid needs. Older adulthood: sarcopenia, reduced thirst, vitamin B12 absorption declining with atrophic gastritis, vitamin D and calcium for bone health, and altered taste/smell.
Traps in questions
- Assuming pregnancy requires "eating for two" (energy increase is modest).
- Mixing up folate (food) and folic acid (supplement/fortificant).
- Forgetting that B12 absorption declines with age even when intake is adequate.
- Treating infant feeding recommendations as one-size-fits-all rather than individualized.
Rule of thumb
Match the life stage to the dominant nutrient concern: folate in early pregnancy, iron in infancy and adolescence, calcium and vitamin D in adolescence and older adulthood, B12 in older adults.
Worked example
A 70-year-old with fatigue and macrocytic anemia despite adequate dietary intake: consider B12 malabsorption from atrophic gastritis and check B12 status before assuming folate deficiency.