Vitamins for the Skin

In order to perform its many functions, the skin and its appendages (hair and nails), require a lush supply of nutrients obtained from our diet.  The skin provides critical protection from infection, external trauma, and ultraviolet damage from the sun; it produces Vitamin D and also helps to maintain moisture and temperature regulation.^[1] Many elements modulate the skin’s functions, structural integrity, and regenerative potential, including genetics, sun exposure, environmental toxins, underlying disease, drug abuse, medications, changes in hormone levels, and diet, just to name a few.  Additionally, the skin contains thousands of microorganisms that ideally live in delicate harmony in and on the skin, which we call a microbiome.^[2] In order to optimally execute its many functions, the skin must have all the necessary vitamin co-factors, either produced by the skin itself or through our diets.  Our bodies have exquisite mechanisms in place to supply some nutrients, such as Vitamin D.  On the other hand, some key vitamins can only be provided by foods and/or supplements.  

The role of vitamins in maintaining skin health has been widely studied, and a diet poor in vitamins can lead to dysfunction in the hair, skin, and nails.  Vitamins can either be fat-soluble (Vitamins A, D, E, K) or water-soluble (Vitamins B and C).  See the table below for some (but not all) of the food sources from which you can obtain each vitamin.

Vitamin A

Vitamin A is required for skin cells (keratinocytes) to properly divide, differentiate, and mature.  Chemical categories similar to Vitamin A include retinoids and carotenoids.^[3,4] Retinoids come mostly from animal food sources, while carotenoids can be obtained from plants.  In order for plant sources of Vitamin A (such as β-carotene) to be active in the skin, it must be converted to the retinoid form.^[5] Vitamin A deficiency has been associated with skin conditions, including poor wound healing^[6,7] and atopic dermatitis.^[8] The oral medication, isotretinoin, is a Vitamin A derivative used to treat severe, resistant acne.^[9] 

Vitamin C

Vitamin C possesses powerful antioxidant activity in its ability to neutralize harmful free radicals that can damage cells.  It may even alleviate damage to the skin caused by the sun’s ultraviolet rays.^[10,11] Vitamin C is an important co-factor in collagen synthesis, thereby having a critical role in wound healing.^[12] In a study of human skin, ingested vitamin C helped with skin hydration.^[13] Vitamin C deficiency leads to a systemic disorder called scurvy, which manifests as easy bleeding and poor wound healing.^[14] 

Vitamin D

Vitamin D has a unique interaction between the skin, liver, and kidneys.  Vitamin D2 (ergocalciferol) is derived from plants and is typically the form added to food.  On the other hand, Vitamin D3 (cholecalciferol) is derived from animal sources and is also made in our skin.  Both types are produced commercially and made into supplements or fortified food.^[15] The physiologically active form is called 1,25-dihydroxy-vitamin D3 and one of its jobs in skin cells (keratinocytes) is to help fight infections.^[16] Additionally, it has been shown to regulate keratinocyte life cycles by inhibiting proliferation,^[17] and it also has a known role in wound healing.^[18]  Vitamin D deficiency can result from not getting enough sunlight, not getting enough in the diet (vegans are at risk), or not absorbing it well in the intestines.^[19] Atopic dermatitis (eczema) has been associated with Vitamin D deficiency.[20,21] 

Vitamin E

Vitamin E is a potent antioxidant. In fact, studies have shown its ability to help alleviate sun damage in skin,^[22] decrease skin cancer risk,^[23] and reduce signs of photoaging.^[24]  Ingested vitamin E may also serve a role as an anti-inflammatory agent in skin.^[25] In animal models, vitamin E deficiencies led to skin ulcerations^[26] and poorly formed collagen.^[27]

B Vitamins

B Vitamins include Vitamin B1 (thiamine), B2 (Riboflavin), B3 (Niacin), B5 (Pantothenic Acid), B6 (Pyridoxine), B7 (Biotin), folic acid, and B12 (Cobalamin).  Niacin deficiency is classically associated with Pellagra, which is a syndrome of a red skin rash in sun-exposed areas, hair loss, and neurological symptoms.^[28] Vitamin B12 deficiency is associated with skin darkening or hyperpigmentation.^[29] Other cutaneous manifestations of B12 deficiency are angular stomatitis (inflammation of the corners of the mouth) and vitiligo.^[30] B vitamins can be found in a large variety of meats, grains, beans, and nuts.  However, Vitamin B12 is only in animal products, which can put strict vegans at risk for deficiency.^[31] 

Vitamin K

Vitamin K plays an essential role in blood clotting, helping the body to heal wounds and bruises. There have been reports that women in Japan who eat fermented natto (rich in Vitamin K2) have fewer wrinkles than age-matched North American women.^[32] Further research is needed to know what role Vitamin K plays in wrinkles.