Nutrition Basics
Micronutrients vs. macronutrients: what's the difference
Macros give you energy and building blocks. Micros keep the machinery running — and you need both.
Two different jobs
Macronutrients — protein, fat, and carbohydrates — are needed in large amounts and supply calories (energy). Micronutrients — vitamins and minerals like vitamin D, iron, calcium, and potassium — are needed in much smaller amounts and don't supply calories, but are essential for things like immune function, bone health, oxygen transport, and hundreds of enzyme reactions.
Why "hitting your macros" isn't the whole story
It's entirely possible to hit a protein/fat/carb target using foods with almost no micronutrient value — and it's equally possible to hit the same targets with foods that are also rich in vitamins, minerals, and fiber. The macro number is the same either way, but the health outcome isn't. That's why food quality still matters even once your macros are dialed in.