Does liposomal vitamin C absorb better?

It's marketed for higher absorption, and there's some early support, but for most people plain vitamin C in divided doses works fine and costs far less.

Can it cause kidney stones?

Very high doses may raise oxalate and, in susceptible people, stone risk. Staying under about 1,000 mg per day avoids the concern for most.

Should I take it with iron?

Yes — vitamin C notably improves absorption of plant-based iron, so pairing them (or taking iron with a citrus food) is a useful trick if you're building iron levels.

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Vitamin C

Vitamin · Also known as: ascorbic acid

Evidence reviewed by Troy Hounshell, PT, ScD · Last reviewed September 8, 2026

A water-soluble antioxidant vitamin needed for immune function and collagen production.

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What it is

Vitamin C is an essential antioxidant your body can't store for long, so a steady intake matters. It's abundant in citrus, peppers, and many vegetables. It's required to build collagen, supports immune cells, and helps you absorb plant-based iron.

How it works

Vitamin C is a water-soluble antioxidant and an essential cofactor. Its best-defined job is helping enzymes build collagen, the protein scaffold of skin, blood vessels, and connective tissue. It also regenerates other antioxidants, supports immune-cell function, and boosts absorption of plant (non-heme) iron when eaten together.

What it's been studied for

Used to support immune function, skin and collagen, and antioxidant defenses.

What the evidence shows

For colds, regular vitamin C doesn't appear to prevent them in most people, but it consistently shortens how long they last. As a cofactor for collagen, it plays a genuine structural role in skin, though supplementing beyond adequate intake adds little.

Who should consider it

Because it's so widespread in produce, outright deficiency (scurvy) is rare in well-fed populations. People most likely to fall short include smokers (who need more), those who eat very few fruits and vegetables, and people with certain malabsorption conditions. Many take it seasonally for immune support or alongside iron to aid absorption.

Amounts commonly studied

Studies often use 200 mg to 1,000 mg per day. Amounts above what the body can use are simply excreted.

How to take it

Studies often use 200-1,000 mg per day. Your body absorbs it best in smaller, divided doses; amounts beyond what you can use are simply excreted. Take it with an iron-rich meal if the goal is better iron absorption. Buffered forms (sodium or calcium ascorbate) are gentler if plain ascorbic acid bothers your stomach.

Forms & absorption

Plain ascorbic acid works well; buffered forms (like sodium or calcium ascorbate) are gentler on the stomach. Liposomal versions are marketed for absorption.

Food sources

Abundant in citrus fruits, bell peppers, strawberries, kiwi, broccoli, Brussels sprouts, tomatoes, and potatoes. A couple of servings of fruit and vegetables usually cover a day's needs.

Safety & interactions

Very safe; high doses can cause loose stools or, rarely, contribute to kidney stones in susceptible people. Space it from certain medications if advised.

Myths & what it won't do

Myth: mega-doses of vitamin C prevent colds. Reality: regular vitamin C doesn't prevent colds in most people — it only modestly shortens them, and loading up once you're already sick hasn't been shown to help much. Myth: more is always better. Reality: past a point your body just excretes the excess, and very high doses can cause diarrhea.

Common questions

Does liposomal vitamin C absorb better?: It's marketed for higher absorption, and there's some early support, but for most people plain vitamin C in divided doses works fine and costs far less.
Can it cause kidney stones?: Very high doses may raise oxalate and, in susceptible people, stone risk. Staying under about 1,000 mg per day avoids the concern for most.
Should I take it with iron?: Yes — vitamin C notably improves absorption of plant-based iron, so pairing them (or taking iron with a citrus food) is a useful trick if you're building iron levels.

The amounts listed here are what published research has used — not a prescription or a recommended dose for you. Confirm anything you plan to take with your own healthcare provider, especially if you take medications, are pregnant or nursing, or have a health condition.

Guides that cover Vitamin C

Research on Vitamin C

Recommendations on this page are informed by published research. This is educational information, not medical advice.

Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013;(1):CD000980. View study →Note: Regular vitamin C doesn't appear to prevent colds in the general population, but it modestly shortens how long they last.

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