Your body needs about 30 different nutrients every day to function properly, and they fall into a few major categories: macronutrients (protein, carbohydrates, and fat), vitamins, minerals, fiber, water, and essential fatty acids. Most people can get everything they need from food alone, but certain nutrients are commonly under-consumed, making it worth knowing what your targets actually are.
Protein, Carbs, and Fat
These three macronutrients supply all of your calories and serve as the structural and energy foundation of your diet. The recommended daily minimums for adults are 46 grams of protein for women and 56 grams for men, along with at least 130 grams of carbohydrates for everyone. There’s no single gram target for fat, but federal dietary guidelines set percentage ranges for all three: 45 to 65 percent of your daily calories from carbohydrates, 10 to 35 percent from protein, and 20 to 35 percent from fat.
On a 2,000-calorie diet, that translates roughly to 225 to 325 grams of carbs, 50 to 175 grams of protein, and 44 to 78 grams of fat per day. These ranges are wide on purpose. Someone who exercises heavily may lean toward the higher end of carbohydrates, while someone focused on muscle maintenance may prioritize the upper end of protein. The minimums exist to prevent deficiency; the ranges exist to give you flexibility based on your goals and preferences.
Essential Fatty Acids
Two types of fat your body cannot manufacture on its own are alpha-linolenic acid (an omega-3) and linoleic acid (an omega-6). You have to get both from food. The adequate intake for omega-3s is 1.6 grams per day for men and 1.1 grams for women, with slightly higher targets during pregnancy (1.4 grams) and breastfeeding (1.3 grams). Good sources include walnuts, flaxseed, chia seeds, and fatty fish like salmon. Omega-6s are abundant in vegetable oils, nuts, and seeds, and most people get plenty without trying.
Vitamins Your Body Needs
There are 13 essential vitamins, split into two groups. Fat-soluble vitamins (A, D, E, and K) dissolve in fat and can be stored in your body. Water-soluble vitamins (C and the eight B vitamins) dissolve in water and are excreted more quickly, which means you need a steady supply from your diet.
Each vitamin plays a distinct role. Vitamin A supports vision and immune function. Vitamin D helps your body absorb calcium and maintain bone density. Vitamin C is involved in tissue repair and immune defense. The B vitamins collectively help convert food into energy, build red blood cells, and support brain function. Vitamin K is essential for blood clotting and bone health. A varied diet that includes vegetables, fruits, whole grains, lean protein, and some dairy or fortified alternatives typically covers all 13.
Key Minerals and How Much You Need
Minerals are divided into major minerals (needed in larger amounts) and trace minerals (needed in smaller amounts). Here are the ones most worth tracking:
- Calcium: 1,000 milligrams per day for most adults ages 19 to 50. Women over 51 and men over 71 need 1,200 milligrams. Dairy products, fortified plant milks, leafy greens, and canned fish with bones are top sources.
- Iron: 18 milligrams per day for women ages 19 to 50 (due to menstrual losses) and 8 milligrams for men and postmenopausal women. Red meat, beans, lentils, spinach, and fortified cereals are reliable sources.
- Magnesium: 310 to 320 milligrams per day for women and 400 to 420 milligrams for men. Nuts, seeds, whole grains, and dark chocolate are rich in magnesium.
- Zinc: 8 milligrams per day for women and 11 milligrams for men. Oysters, beef, chickpeas, and pumpkin seeds are good sources.
- Potassium: 2,600 milligrams per day for women and 3,400 milligrams for men. Bananas, potatoes, beans, and avocados can help you reach that target.
Nutrients Most People Fall Short On
Globally, iron, zinc, vitamin A, and folate are the nutrients people most commonly lack. A 2024 analysis published in The Lancet Global Health found that more than one in two children under five are deficient in iron, zinc, or vitamin A, and two in three women of reproductive age are deficient in iron, zinc, or folate. These gaps aren’t confined to developing countries. Iron deficiency is the most common cause of anemia worldwide, leading to fatigue, impaired concentration, and complications during pregnancy.
Folate deserves special attention for anyone who may become pregnant. It plays a critical role in the earliest weeks of fetal development, reducing the risk of neural tube defects and stillbirth. Because the need arises before many people know they’re pregnant, maintaining adequate folate intake consistently matters more than starting a supplement after a positive test. Leafy greens, legumes, and fortified grains are strong dietary sources.
Fiber and Water
Fiber is technically a carbohydrate, but your body doesn’t digest it. Instead, it feeds beneficial gut bacteria, regulates blood sugar, and keeps your digestive system moving. Most adults need 25 to 30 grams of fiber per day, though the average American gets only about 15. Whole grains, fruits, vegetables, beans, and nuts are the best sources. An interesting bonus: certain types of fiber (like inulin, found in garlic, onions, and bananas) can actually improve mineral absorption by feeding gut bacteria that lower the pH in your large intestine, helping dissolve mineral compounds that would otherwise pass through unused.
For water, the general targets are about 11.5 cups (2.7 liters) of total fluid per day for women and 15.5 cups (3.7 liters) for men. That includes all fluids and the water content in foods, which typically accounts for about 20 percent of your intake. Your actual needs shift with climate, exercise, illness, and body size.
What to Limit
The 2020-2025 Dietary Guidelines for Americans set three clear limits. Added sugars should stay below 10 percent of your daily calories, which works out to under 50 grams (about 12 teaspoons) on a 2,000-calorie diet. Saturated fat should also stay below 10 percent of calories, meaning roughly 22 grams per day. Sodium should stay under 2,300 milligrams, or about one teaspoon of table salt. Most people exceed all three of these limits regularly, primarily through processed and restaurant foods rather than home cooking.
How Nutrient Needs Change
Your age, sex, activity level, and life stage all shift what your body requires. Women of childbearing age need more than double the iron that men do. Older adults need more calcium and vitamin D to protect bone density. Pregnant and breastfeeding women have higher targets for folate, iron, iodine, and omega-3 fatty acids. Iodine is particularly important during pregnancy and lactation because it directly supports fetal and infant brain development.
Physically active people burn more calories and lose more electrolytes through sweat, which increases their needs for carbohydrates, potassium, sodium, and water. They may also benefit from higher protein intake to support muscle repair, though the broad recommended range of 10 to 35 percent of calories gives plenty of room to adjust upward without special supplements.
Getting More From Your Food
Not all nutrients are absorbed equally. The fraction of a nutrient your body actually takes in, called bioavailability, depends on what else you eat alongside it, the chemical form of the nutrient, and your own digestive health. Fat-soluble vitamins (A, D, E, K) absorb better when eaten with some dietary fat, so drizzling olive oil on a salad or eating carrots with hummus makes a practical difference. Vitamin C enhances iron absorption from plant sources, which is why squeezing lemon over lentils or pairing beans with bell peppers is a useful habit, especially for vegetarians.
On the flip side, certain compounds can block absorption. Calcium and iron compete for the same absorption pathways, so taking both in a single high-dose supplement is less effective than spacing them out. Tannins in tea and coffee can also reduce iron uptake if consumed with meals. These interactions rarely matter if your overall diet is varied, but they become more important if you’re relying on a narrow range of foods or managing a known deficiency.