The main function of the skin is to act as a barrier between the environment and your insides. To understand this is to also understand that your skin takes a beating!
Your skin protects you from the following: 
- provides shielding from mechanical and chemical threats
- ultraviolet radiation
The skin is composed of two layers: the outer layer is highly cellular and is part of the barrier function and the inner layer ensures strength and elasticity and gives nutritional support to the epidermis . Normal and healthy skin contains high concentration of vitamin C which support various function such as: 
- stimulating collagen synthesis
- assisting in antioxidant protection against UV-induced photodamage damage
The skin is the largest organ of our bodies and reflects the general health of the person. Due to the skins constant contact with the outside world, it is the first organ that begins to show signs of aging.
Nutrients and Skin Health
Micronutrients and macronutrients are so important for the health and appearance of the skin. This can be visibly proved by a variety of nutrient deficient skin issues. 
- Vitamin B deficiency can result in a patchy red rash
- Vitamin C deficiency can result in skin fragility, bleeding gums, and corkscrew hair.
The skin has its challenges when trying to deliver nutrients, the outer layer is tough and has limited to no vascularization, because of this it is hard to get nutrients to the outer layer. Using topicals and lotions may not be enough when delivering concentrations of vitamins to the skin. It is hypothesized that delivery of nutrients need to come through the under lying dermis from blood vessels.
“Several reports have indicated that vitamin C levels are lower in aged or photo damaged skin.”
Levels of Vitamin C are believed to be in concentrations that reflect a gradient (in the skin). The outer later of the epidermis have the lowest levels of vitamin C while the inner layers have the highest concentrations of vitamin C. This is a possible reflection of the depletion in the outer cells due to chronic exposure to the environment .
Topical application of Vitamin C, Does it work?
Vitamin C is a water-soluble and charged molecule because of this, it is repelled by the barrier of terminally differentiated epidermal cells . Vitamin C can only penetrate the skin when its pH is low (below 4). Having a low pH makes the quality of something more acidic. Which makes sense since Vitamin C is ascorbic acid. This is the only chance vitamin C has at penetrating its nutrients deep into the skin.
“Recent studies suggest that encapsulation into a lipospheric form may assist with transport into the lower layers of the epidermis and could result in increased uptake.”
One of my favorite supplements is the Liposomal Vitamin C by OPTIMUNITY. This particular vitamin is delivered through a liposome, which is also a lipospheric encapsulation- it is a lipid delivery. Is this the best way at delivering vitamin C? Seems likely.
What happens to our skin when we are Vitamin C deficient?
If anyone has ever had a food allergy and seen a gastrointestinal doctor for it, what is the first thing they suggest? Usually- an elimination diet is suggested. This means, you take a certain food group away and then reintroduce it after weeks of detox. If the particular food group causes a reaction – you are probably sensitive to it.
So what happens to our skin when we don’t have vitamin C?
- poor wound healing due to loss of collagen formation
- skin thickening
- subcutaneous bleeding due to fragility and loss of connective tissue morphology
All three of these conditions are extreme and rapid in onset in Vitamin C deficient individuals. 
Skin aging is complex and can be accelerated by a number of exogenous (outside the body) and endogenous (inside the body) factors. 
- cellular metabolism
- hormone and metabolic processes
- chronic light exposure
- ionizing radiation
- chemicals and toxins
The skin can show aging in a few different ways. Sometimes our skin thins as we age and becomes finely wrinkled while Photo damaged skin is typically thickened, discolored, and has deep wrinkles and then there is sagging skin.
The loss of the structure and function of collagen causes sagging skin- what combats the loss of collagen integrity? Vitamin C!!
Vitamin C and Collagen
Collagen is a fibrous, supportive protein. It is found in all of the connective tissue in the body including the skin. It helps skin cells stick to one another which also give strength and elasticity to the skin. Collagen production diminishes with age and this contributes to skin wrinkling and sagging.
How does vitamin C promote collagen production?
- Vitamin C acts to stabilize the collagen molecular
- Vitamin C also promotes collagen gene expression
- The dependence of collagen enzymes on vitamin C has been demonstrated in a number of studies 
- There has been evidence of decreased total collagen synthesis and decreased cross linking when vitamin C is not available.
There is also evidence that suggest vitamin C increase proliferation (multiplying) and movement of dermal fibroblasts ( a cell that synthesizes collagen) – Vitamin C has the ability to restructure the elasticity of the skin. Its such an impressive nutrient! And a way less invasive anti aging product compared to injectables!
Vitamin C as an Antioxidant
Vitamin C is a powerful antioxidant that can actively remove oxidants caused by environmental pollution. Oxidants are also known as reactive oxygen species (ROS). ROS are exactly how they sound- the are reactive! meaning they are unstable and they wreak havoc on our DNA.
Which is probably why vitamin C is in a lower concentration on the out layer of the skin. It is being utilized to round up the ROS that are accumulating from UV light and from pollution.
Utilizing vitamin C supplements increase the concentration in the plasma and thus it increases the concentration in the vascular areas of the skin. Increased vitamin C helps round up the oxidants that causes pre mature aging in the cells of the skin.
Vitamin C and Hyperpigmentation
Melanin is a natural pigment found in most animals, it give color to our skin, hair, and eyes. We get tan after laying in the sun due to production of melanin. Melanin increase after exposure to the sun in order to help dissipate absorbed UV radiation. Laying in the sun too much can cause melanin to begin to clump and darken which forms moles. A mole that changes over time can become malignant. This melanin is what causes the hyperpigmentation in our skin.
“Vitamin C derivatives have been shown to decrease melanin synthesis both in culture melanocytes and in vivo.”
Vitamins such as vitamin C are used to decrease melanogenesis, these agents are used to treat skin hyperpigmentation. 
Vitamin C Is essential in helping combat hyperpigmentation. Another way Vitamin C is one of the best beauty products!
Maintaining the integrity of the Skin has its Challenges
Over a lifetime the skin is exposed to so many challenges that affect its structure function and appearance. 
- Deterioration due to normal aging this is due to loss of collagen production and loss of elasticity which forms wrinkles and sagging
- Exposure to weather elements; the sun can cause dryness and deceleration, the cold and wind can lead to dryness, think skin, and wrinkling.
- Chemical exposure- hair dyes, soaps, detergents, and bleaches
- Direct injury, wounds and burns.
Vitamin C has been proven to protect against many if not all of the abuses our skin takes.
According to a variety of studies complied by Pullar Et. al. Vitamin C helps in anti aging and for medicinal purposes.
- Sunburn – improving skin vitamin C and E levels can improve resistance to UV exposure
- Photo-aging– decreased signs of aging with higher fruit and vegetable intake
- Hyperpigmentation– nutrition studies show imported skin color with high fruits and vegetable intake high in vitamin C
- Wrinkle formation – Lessening of wrinkle depth following Vitamin C supplementation
- Skin sagging– Improved skin tightness in individuals with higher fruit and vegetable intake high in vitamin C
- Surface roughness– Vitamin C enhances production of barrier lipids in cell culture
- Dry skin– Vitamin C enhances production of barrier lipids in cell culture
- excessive scar formation– Supplementation improves wound healing, prevents keloid formation, enhances collagen formation
- Poor wound healing– direct association with Vitamin C deficiency prevents wound healing
- Inflammation of the skin– Nutrition support decreased levels associated with loss of barrier lipid ceramide.
Good skin health is positively associated with a healthy lifestyle, high levels of fruit and vegetable intake along with exercise and hydration (with water) is imperative. Water is key!! The positive benefits of of fruits and vegetables are due to an abundance of different nutrients and vitamin C is one of the main healthy components!
“Signs of aging in human skin can be improved through the provision of vitamin C. A number of studies support this…”
Vitamin C also greatly helps wound healing and minimizes the appearance of scars, as well as aiding in the work of fibroblasts, which synthesize collagen. Extra Collagen means no sagging skin!
Delivery of topical Vitamin C is very difficult for a number of reasons, its hard for vitamin C to penetrate the skin If the pH of the product is too high. As well as, the barrier that the outer layer of the skin provides. Taking supplemental Vitamin C is essential for delivery of vitamin C.
Vitamin C is also imperative for removing ROS/free radicals from the body. It is such a powerful antioxidant, because of this it helps skin heal from the damage and the excess ROS that sun exposure causes. Vitamin C, essentially helps protect and heal you from sun exposure.
- Vitamin C removes reactive oxygen species during and soon after sun exposure.
- If you’ve been exposed to the sun too much, it helps eliminate hyperpigmentation.
All in all- Vitamin C is the best beauty product!