Micronutrients: The Vitamins & Minerals That Matter for Skin & Healthy Aging

Written by Empire Medical Training Editorial Team

Medically reviewed by Mark Tager, MD Integrative & Functional Medicine Physician; Author, ‘Feed Your Skin’

Updated June 2026 ·11 min read

Macronutrients build the body; micronutrients run it. Vitamins and minerals are needed in small amounts, but they sit at the center of nearly every process that keeps skin resilient and aging gracious — collagen synthesis, antioxidant defense, immune signaling, energy metabolism, and cell renewal. When they fall short, the body often tells you first at the surface: in the skin, the hair, the nails, and the tongue. Reading those signals, and correcting them sensibly, is a core clinical skill.

This guide is part of Empire Medical Training's Precision Nutrition resource cluster and reflects the clinical framework taught by Dr. Mark Tager, MD, an integrative and functional medicine physician and author of Feed Your Skin. It is clinical education, not medical advice. Nutrition supports — but does not replace — medical diagnosis and treatment, and several findings below warrant a formal work-up rather than a supplement.

Why micronutrients matter for skin and aging

By completing a precision-nutrition framework, a clinician learns to review macro- and micronutrients and their role in well-being. Micronutrients earn that attention because they are cofactors — the small molecules without which larger reactions simply stall. Vitamin C is required to form healthy collagen fibers; in its absence, collagen forms abnormal fibers. Zinc supports immune function and skin renewal. The B vitamins power energy metabolism. Selenium and vitamin E protect cell membranes from oxidative damage. None of this is optional machinery, and none of it works in isolation — the nutrients function as an interdependent system, which is exactly why a food-first, whole-diet approach outperforms chasing one nutrient at a time.

The aging body raises the stakes. With age we see declines in collagen, elastin, muscle mass, bone density, and digestive enzymes — and reduced stomach acid (hydrochloric acid) impairs absorption of B12, iron, calcium, folic acid, vitamin C, and vitamin D. The need does not fall with age; the ability to extract nutrients often does. That gap is precisely where careful assessment and, where indicated, targeted repletion belong.

The key vitamins: A, C, D, E and the B-complex

A handful of vitamins do disproportionate work for skin and healthy aging. Here is the clinical shorthand, kept food-first.

Vitamin A (retinoids)

The term vitamin A covers a group of retinoids — retinol, retinal, and retinyl esters. In the skin it is central to cell turnover and renewal, and the body can also make it from beta-carotene found in carrots, sweet potatoes, and squash (though the efficiency of that conversion varies genetically from person to person). White spots on the conjunctiva can signal a vitamin A deficiency. Because vitamin A is fat-soluble and stored, it is one of the vitamins where excess supplementation can cause harm — a reason to favor food and documented need over high-dose pills.

Vitamin C

Vitamin C is one of the most skin-relevant micronutrients there is. It contributes to healthy collagen and improves the firmness of the skin, and as a potent antioxidant it can reduce skin inflammation by neutralizing free radicals. Critically, the body cannot manufacture vitamin C, so it must come from the diet — citrus, peppers, and many fruits and vegetables. Its collagen role connects micronutrients directly to structural skin aging, a theme we expand on in collagen supplements.

Vitamin D

Vitamin D is among the most common shortfalls in the United States — by national survey data, the large majority of Americans do not meet even the estimated average requirement. It is fat-soluble, which again means status and dose matter rather than blanket megadosing. Because its biology (activation, transport, and target-cell delivery) is genuinely individual, vitamin D earns its own deep dive: see vitamin D and skin health.

Vitamin E

Vitamin E is the fat-soluble antioxidant found in nuts, seeds, and green leafy vegetables, where it helps protect cell membranes from oxidative damage. As with the other antioxidants, the food-first rule holds: the protective signal is clearest from a whole-food matrix, and high-dose isolated supplements are where the evidence gets shaky.

The B-complex and B12

The B vitamins — thiamin, riboflavin, niacin, B6, folate, and B12 among them — run energy metabolism and a long list of skin-relevant pathways. B6, for instance, helps reduce sebum production, which is why acne-prone patients may benefit from supplementing up to the tolerable upper intake level (a defined ceiling — not an open invitation to megadose). B12 deserves special attention: it is poorly absorbed when stomach acid is low, depleted by common medications such as acid-suppressing PPIs and H2 blockers, and frequently low in vegans and vegetarians, who also tend to run short on iron, calcium, protein, zinc, and vitamin D.

The key minerals: zinc, magnesium, iron, selenium

Minerals are the other half of the micronutrient story, and several are foundational to skin and healthy aging.

• Zinc — supports immune function and skin renewal; involved in skin barrier integrity and wound healing. Low zinc is implicated in dandruff, thinning hair, and the keratosis-pilaris pattern discussed below. Found in oysters, red meat, legumes, seeds, and whole grains.
• Magnesium — supports muscle and nerve function and hundreds of enzymatic reactions; roughly six in ten Americans fall below the average requirement. It is depleted by PPIs, which can drive fatigue, and low magnesium can produce muscle cramps and irregular heartbeats. Found in leafy greens, nuts, seeds, and whole grains.
• Iron — essential for oxygen transport. Iron deficiency is a major issue for menstruating and pregnant women; it can present as brittle or spooned nails, slow capillary refill, dull hair, and is a common, correctable contributor to hair loss. Ferritin reflects iron storage and is especially worth checking in women.
• Selenium — supports metabolism and immune function and is part of the body's antioxidant defenses; found in whole grains, seafood, and Brazil nuts. Like the fat-soluble vitamins, it has a relatively narrow window — more is not better.

A theme worth naming: the nutrient content of produce itself has declined over the second half of the twentieth century, with measurable drops in minerals and vitamins such as phosphorus, iron, and vitamin C in many fruits and vegetables. That reduction can contribute to shortfalls even when patients eat enough calories — one more reason assessment matters.

How deficiency presents — reading the skin, hair, and nails

One of the most clinically useful ideas in Dr. Tager's framework is that the surface reports deficiency before the serum does. The skin, hair, nails, and even the tongue function as an external dashboard.

The signature example is keratosis pilaris — the rough, raised bumps on the skin, often alongside small white spots on the nails (hyperkeratosis). This constellation can indicate insufficient levels of zinc, vitamin A, and essential fatty acids together — a reminder that real-world deficiencies travel in clusters, not as single nutrients.

Other patterns clinicians learn to read:

• Dry, flaky skin — often points to an essential-fatty-acid imbalance or vitamin deficiency.
• Dandruff — associated with low essential fatty acids and zinc.
• Thinning hair / alopecia — may reflect zinc and iron deficiency, or simply inadequate protein; dull hair can signal low protein or iron, and premature graying is associated with copper and B12.
• Brittle or spooned nails, slow capillary refill — classic iron-deficiency clues.
• The tongue — one of the first places mineral deficiencies appear before serum: scalloping can flag low B vitamins, iron, niacin, and riboflavin; a geographic tongue can clue you in to zinc, iron, folic acid, B6, or B12 deficiency.

These are clues that prompt assessment, not diagnoses on their own. And some surface findings have nothing to do with nutrition — which is why scope matters. Unintended weight loss, signs of malabsorption (as in celiac disease), or severe deficiency signs deserve a medical work-up, not a supplement guess.

Food first — where the micronutrients live

The first and best source of micronutrients is a varied, minimally processed diet. Whole grains alone supply B vitamins (thiamin, riboflavin, niacin, folate), vitamin E, and the minerals iron, magnesium, phosphorus, selenium, and zinc. Leafy greens deliver magnesium, folate, and vitamin E; citrus and peppers supply vitamin C; colorful produce provides carotenoids; and animal foods such as eggs, dairy, fish, and seafood are reliable sources of B12, iron, zinc, and vitamin D — the very nutrients plant-only diets most often miss.

This food-first stance is not anti-supplement; it is pro-priority. Whole foods deliver nutrients in their natural ratios and synergies, which is why the strongest evidence for antioxidants, in particular, is for food rather than isolated high-dose pills. We treat that subject in depth in antioxidants and oxidative stress, and the essential-fat side of the equation in omega-3 fatty acids and skin.

Testing and repletion — when supplements make sense

When history and exam suggest a shortfall, objective testing sharpens the picture. Basic panels from standard labs can reveal a great deal: a CBC can shed light on B6 and B12 status, a 25-hydroxy vitamin D test checks vitamin D, serum iron and ferritin assess iron stores, and elevated homocysteine can indicate B-vitamin deficiencies. Some minerals are best measured inside the cell — a red-blood-cell zinc test reflects status over three to four months, and an RBC magnesium test is often more accurate than serum, because the body pulls magnesium from cells into the blood when it is depleted, masking a true deficit. The specifics of which tests to order, how to interpret them, and how to build a repletion plan are taught in Empire's course rather than reproduced here as a turnkey recipe.

Once a deficiency is documented, repletion can be targeted and, importantly, bounded. This is the practical home of the food-first, evidence-honest stance: correct what is low, recheck, and avoid the reflex to megadose. For the broader supplement landscape — quality, forms, and how nutraceuticals fit a plan — see nutraceutical supplementation, and for the assessment workflow itself, nutritional assessment and lab testing.

"More is not better" — the toxicity and overclaiming reality

Nutrition marketing runs on the idea that if a little is good, more must be better. Clinically, that is false — and sometimes dangerous. Dr. Tager states his stance plainly: very few people need or benefit from megadoses of vitamins.

The clearest risk is with the fat-soluble vitamins — A, D, and E. Because they are stored in the body rather than readily excreted like the water-soluble vitamins, excess supplemental intake can accumulate to toxic levels. High-dose isolated antioxidant supplements are another cautionary tale: outside of correcting a deficiency, they can be useless or, in specific populations, harmful. Where appropriate, baseline blood tests can establish status before repletion and check for the rare-but-real toxicities of over-supplementation. Two more practical guardrails: dose to a defined ceiling (the tolerable upper intake level) rather than past it, and screen for drug–nutrient interactions — for example, certain supplements interact with anticoagulants, and many common medications deplete nutrients in the first place.

None of this argues against supplementation — it argues for precision. The right nutrient, for the right person, at the right dose, to correct a real deficiency. That is the entire point of a precision approach, and it is what Empire's training is built to teach.