Vitamin C Absorption: Why How You Take It Matters
By Mitchell J. Ghen, D.O., Ph.D. & Irena Y. Ghen, MSN, APRN-BC
Vitamin C may be the most familiar vitamin in the world. Yet most people take it in a way that leaves much of it unused. Here is what actually happens after you swallow vitamin C, and how to get more from every dose.
Why Your Body Depends on Vitamin C Every Day
Most animals make their own vitamin C. Humans cannot: the gene for the final step of that process is switched off in us. That means every milligram your body uses has to come from food or supplements.
And your body uses plenty. Vitamin C supports normal immune function, it is required to build collagen for skin, joints, blood vessels and gums, and it is one of your main antioxidants, helping protect cells from oxidative stress. Some of the body’s highest concentrations are found in the adrenal glands and the brain, and stress increases how much you use.
How Your Body Absorbs Vitamin C (and Why More Isn’t Always More)
Vitamin C is absorbed in the small intestine by transporters that can only move so much at once. At modest intakes, most of what you take is absorbed. As the single dose gets larger, the percentage absorbed falls, and the kidneys excrete the excess within hours.
In practice, the milligrams on a label are not the same as the vitamin C that reaches your cells. How and when you take it matters.
Water-Soluble vs. Fat-Soluble Vitamin C
Standard vitamin C, ascorbic acid, dissolves in water. That is useful in the bloodstream, but every cell in your body is wrapped in a membrane made largely of fats.
Ascorbyl palmitate is vitamin C bonded to palmitic acid, a fatty acid. That bond makes it fat-soluble. A 2024 scientific review in the journal Process Biochemistry describes its lipophilic (fat-loving) properties, its wide use as an antioxidant, and the encapsulation techniques used to protect and deliver it. Read the review here.
What Is Nano Vitamin C?
“Nano” refers to particle size. Through a proprietary micronization process, the raw materials in our Nano Vitamin C are reduced to under 100 nanometers, designed to support absorption and use of the vitamin C. Each capsule combines both forms, water-soluble ascorbic acid and fat-soluble ascorbyl palmitate, for a total of 800 mg of vitamin C.*
5 Ways to Get More From Your Vitamin C
- Eat your colors daily. One cup of chopped red bell pepper has more than double the vitamin C of a medium orange. Kiwi, strawberries, broccoli and citrus are excellent too.
- Take supplements with food. It is gentler on the stomach and supports absorption.
- Spread it out. Several smaller amounts across the day are retained better than one large dose.
- Pair it with plant iron. Vitamin C helps your body absorb iron from plant foods. Add peppers to beans or lemon to leafy greens.
- Be consistent. Your body can’t make vitamin C and stores relatively little, so daily intake matters more than occasional large doses.
How Much Vitamin C Do You Need?
The U.S. Recommended Dietary Allowance is 75 mg per day for women and 90 mg for men, with an extra 35 mg for people who smoke. The Tolerable Upper Intake Level for adults is 2,000 mg per day from all sources. Many people choose more than the RDA for wellness support; your healthcare provider can help you find the amount that’s right for you.
Where Nano Vitamin C Fits
Food always comes first. For days when your plate isn’t perfect, or when you want daily support for immune function, collagen formation and antioxidant defense, Nano Vitamin C offers both forms of vitamin C in one physician-formulated, vegan-friendly capsule.* Take 1 capsule 1–3 times daily with food, or as directed by your healthcare provider. It is third-party tested and made in the USA in an FDA-registered cGMP facility.
Your Next Step
Vitamin C is one piece of the bigger picture. Take our free 10-question Longevity & Wellness Quiz to get your personalized Longevity Blueprint, or download the free Foundations of Longevity guide to explore all 10 Pillars of Health.
Safety note: If you are pregnant or nursing, have a history of kidney stones, have an iron-storage condition, have any medical condition, or take any medications, consult your healthcare provider before taking vitamin C supplements.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is educational and is not a substitute for advice from your healthcare provider.
