Nutrient Gaps Most Americans Actually Have — and the Foods That Fill Them

Vitamin D supports bone health, immune function, and may play a role in mood regulation. Yet NHANES data consistently shows that a large proportion of US adults have insufficient blood levels — partly because few foods naturally contain meaningful amounts, and partly because many people have limited sun exposure year-round.

Food sources to prioritize:

• Fatty fish such as salmon, mackerel, and sardines
• Egg yolks (particularly from pasture-raised hens)
• Fortified milk, plant-based milk alternatives, and some breakfast cereals
• Canned tuna (also provides omega-3s and protein)

Because dietary sources alone rarely hit recommended levels for many people, a healthcare provider may assess blood levels and recommend supplementation if warranted — but that decision should be guided by individual testing, not assumption.

Calcium is essential for bone density, muscle contraction, and nerve signaling. While dairy is the most well-known source, non-dairy eaters often fall significantly short. Absorption also matters: vitamin D helps the body absorb calcium, so the two deficiencies frequently co-occur.

Food sources to prioritize:

• Dairy products — milk, yogurt, and cheese
• Fortified plant milks (soy, oat, almond)
• Canned fish with soft, edible bones (salmon, sardines)
• Tofu made with calcium sulfate
• Leafy greens like bok choy, kale, and broccoli (though absorption varies)

Spinach and Swiss chard contain calcium but also oxalates that reduce absorption — they're still nutritious, just not the most efficient calcium sources.

Potassium helps regulate blood pressure, supports fluid balance, and is critical for heart and muscle function. Most Americans consume far less than the adequate intake of 2,600–3,400 mg per day (depending on age and sex), largely because potassium is concentrated in fruits, vegetables, and legumes — food groups that tend to be under-represented in typical US eating patterns.

Food sources to prioritize:

• Beans and lentils (among the richest dietary sources)
• Potatoes and sweet potatoes (with skin)
• Bananas, avocados, and dried apricots
• Winter squash and leafy greens
• Yogurt and milk

Cooking vegetables reduces potassium content somewhat (it leaches into water), so steaming or roasting preserves more than boiling. See budget-friendly strategies for eating more whole foods to incorporate legumes and produce affordably.

Magnesium participates in over 300 enzymatic reactions in the body, including energy production, DNA synthesis, and muscle and nerve function. Refined grains and processed foods are largely stripped of magnesium during manufacturing, which helps explain why many Americans consume less than the recommended 310–420 mg per day.

Food sources to prioritize:

• Pumpkin seeds (pepitas) — one of the most concentrated sources per serving
• Whole grains such as brown rice, quinoa, and whole wheat
• Dark chocolate (70%+ cacao)
• Legumes including black beans and edamame
• Nuts, especially almonds and cashews
• Leafy greens like spinach

Choosing whole grains over refined grains is one of the most straightforward ways to increase magnesium intake without dramatically changing eating patterns.

Dietary fiber supports digestive health, helps maintain healthy blood sugar and cholesterol levels, and feeds beneficial gut bacteria. Despite its importance, average US adults consume roughly half the recommended daily amount (25 g for women, 38 g for men). Ultra-processed foods — which now account for the majority of calories in many American diets — are typically low in fiber.

Food sources to prioritize:

• Legumes (black beans, chickpeas, lentils) — among the highest fiber foods available
• Whole grains (oats, barley, whole wheat bread and pasta)
• Vegetables, especially Brussels sprouts, broccoli, and artichokes
• Fruits with edible skins, seeds, or membranes (berries, apples, pears)
• Nuts and seeds

Increasing fiber intake gradually — rather than all at once — helps avoid digestive discomfort. Hydration also matters: fiber works best when paired with adequate fluid intake. For a deeper look at how specific nutrients function in the body, the micronutrient reference guide covers vitamins and minerals at a glance.