But NOT capsules of ascorbic acid mixed with powdered rose hips (to make it sound "natural").

REAL "natural" Vitamin C.

Thanks to the efforts of 2-time Nobel Laureate Linus Pauling, Vitamin C is the most well-known vitamin of them all, and usually considered the most important.

Pauling focused his attention on promoting Vitamin C as the cure for everything from the common cold to cancer. 

In general, science has not accepted his extreme views, but nobody doubts Vitamin C is essential for people to consume for optimal health.

And it's also vital to consume - both by eating and by applying topical serums - for optimal skin health and beauty.

Benefits of Vitamin C for Your Skin:

1. Boosts production of collagen

This is probably most important, because collagen makes up 70% of your skin.

It's the protein that holds your skin (and you) together.

Your body manufactures collagen for your skin, but this (naturally) declines with age.

It declines even faster if you're not consuming adequate amounts of Vitamin C, because collagen synthesis can't happen without Vitamin C.

That's because Vitamin C is an essential cofactor for two essential enzymes:

* Prolyl hydroxylase - stabilizes collagen molecules

* Lysyl hydroxylase - strengthens collagen's structure

Without adequate Vitamin C to make adequate collagen, your skin is like a bowl of ice cream in the sun.

When collagen declines, your skin tone weakens, becoming thinner. Your skin droops and sags. You display fine lines and crow's feet - and then out and out wrinkles. 

2. Reduces inflammation - redness, itchiness and irritation

Vitamin C is a powerful antioxidant. It neutralizes the free radicals inflaming your skin in such conditions as: rosacea, sunburn, eczema and even acne.

That was verified by a review study done in 2015.

According to a review done in 2017, when your skin is damaged, Vitamin C promotes cell turnover. That is, the replacement of damaged cells with healthy new cells. When your skin is hurt, Vitamin C helps heal it.

Your skin is the organ of your body most exposed to the stresses of the outside world: dry air, polluted air, extremes of temperature, smoke, other particulates and toxic substances from certain modern plastics to poison ivy. Your skin may also reflect the emotions you're undergoing in life.

These stresses activate your immune system to launch an inflammatory response. Vitamin C helps smooth out your immune system.

Vitamin C helps your skin cope with all these problems, so your skin remains smooth, clear and evenly pigmented.

3. Hydrates your skin

What's the difference between a plum and a prune? Just water.

We all know people with plum(p) skin. They're mostly young, but some are older folks who work at keeping their skin hydrated.

And we all know people - mostly though not all - older, who remind us of prunes.

According to a review done this year, Vitamin C applied topically reduces transepidermal water loss (TEWL). In a 2019 study, a serum containing Vitamin C reduced TEWL by 19%.

Skin Vitamin C from Your Diet

Your main source of Vitamin C is the foods you eat.

Oranges have a reputation for having high amounts of Vitamin C, but don't think of food as a form of vitamin supplementation.

Almost all plant foods - unless highly processed like white grains, sugars and oils - contain Vitamin C.

In general, the stronger the color, the more Vitamin C (and other antioxidants and nutrients) a plant has.

Thus, oranges contain more Vitamin C than bananas. Sweet potatoes contain more Vitamin C than white potatoes. Black beans contain more Vitamin C than white beans.

To max out your daily intake of Vitamin C, eat plenty of whole grains, beans, nuts, fruits and vegetables.

To make sure your skin gets plenty of Vitamin C, however, apply a topical Vitamin C serum AS WELL AS eating plenty of fruits and vegetables. (The serum DOES NOT make up for not eating Vitamin C-rich foods.)

What to Look for in a Vitamin C Serum:

1. The formulation is water-free - and comes in an opaque, airtight bottle.

2. Make sure the label says "FDA Certified Organic" for products sold in the US. If you're outside the US, look for the equivalent in your country.

By themselves, the words "organic" or "all-natural" on the label are MARKETING - not a promise the product is safe.

Related to this, avoid all synthetic or toxic ingredients - READ THE LABEL.

3. Choose natural ingredients rich in Vitamin C.

These include:

* Indian gooseberry. (Phyllanthus emblica). Also known as amla, the Indian gooseberry is a small green fruit eaten in India, and used in Ayurvedic medicine for thousands of years. If you ever try powdered amla - available in Indian and Pakistani food stores - you'll experience immediately what a powerful plant it is. A little goes a long way.

* Camu camu. (Myciaria dubia). This is a small fruit that grows in the Amazon rain forest. It's the second-richest source of Vitamin C in the world. And it contains flavonoids and carotenoids you skin will also love.

* Mango seed butter. This is made by crushing the big, hard seeds in the middle of mangoes. This butter is much like shea butter, and is rich in Vitamin C. Plus Vitamins A & E, more antioxidants and fatty acids your skin soaks up like a thirsty sponge.

* Rosehip seed oil. Rosehips form on rose plants late in the season. They're packed with Vitamin C, which is why they're added to plain old ascorbic acid to create Vitamin C supplements that claim to be natural. They're also loaded with fatty acids that hydrolyze your skin, making it more elastic.

* Acai berries. A few years ago, a lot of online scammers promoted acai berries as a weightloss supplement. There's no evidence for that, but they are undoubtedly rich in Vitamin C. They're tiny purple berries from the rain forests of Central and South America.  

https://theartofantiaging.com/vitamin-c-benefits-for-skin-and-5-best-vitamin-c-ingredients/

https://en.wikipedia.org/wiki/Linus_Pauling

https://www.healthline.com/health/beauty-skin-care/vitamin-c-serum-benefits

https://www.health.harvard.edu/blog/why-is-topical-vitamin-c-important-for-skin-health-202111102635

https://www.webmd.com/beauty/ss/slideshow-benefits-of-vitamin-c-for-skin

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579659/