WE LOVE TRANSPARENCY

As a leading innovator in the skincare and wellness industry, Cera Secrets is dedicated to developing cutting-edge products that harness the power of science and nature to improve skin health and overall well-being. With a focus on research-driven solutions and sustainable, ethically-sourced ingredients,
We are committed to empowering individuals to embrace their natural beauty and nurture their skin from the inside out.

COCERA™ is formulated with a proprietary blend of natural patented wheat ceramides complex, antioxidants, and other essential nutrients that work synergistically to support healthy skin from within. The inside-out approach targets the skin at a cellular level, providing deep hydration, improved barrier function, and enhanced elasticity. Clinical studies have demonstrated that the regular consumption of COCERA™ leads to visible improvements in skin texture, hydration, and overall appearance.

Please feel invited to get more detailed information about our patented Ceramides complex and our ingredients inside COCERA:

PHYTOCERAMIDES (PATENTED COMPLEX)

Guillou, S., Ghabri, S., Jannot, C., Gaillard, E., Lamour, I., & Boisnic, S. (2011). The moisturizing effect of a wheat extract food supplement on women’s skin: a randomized, double-blind placebo-controlled trial. International Journal of Cosmetic Science, 33(2), 138-143. https://doi.org/10.1111/j.1468-2494.2010.00600.x
This study demonstrated that oral supplementation with wheat extract containing ceramides significantly improved skin hydration in women after 3 months of treatment compared to the placebo group.

Boisnic, S., Beranger, J. Y., & Branchet, M. C. (2007). Clinical and biometrological assessment of the efficacy of a food supplement on skin dryness and skin barrier function. European Journal of Dermatology, 17(6), 519-522. https://doi.org/10.1684/ejd.2007.0297
This clinical study found that oral supplementation with a wheat extract containing ceramides improved skin barrier function, reduced trans-epidermal water loss (TEWL), and increased skin hydration in subjects with dry skin.

Meyer, L., Gaudin, A., & Berger, M. (2021). Effects of an oral supplementation with wheat ceramides on clinical signs and biochemical markers in women with xerosis: Results of a randomized, double-blind, controlled pilot study. Journal of Cosmetic Dermatology, 20(7), 2105-2111. https://doi.org/10.1111/jocd.14018
In this randomized, double-blind, controlled pilot study, oral supplementation with wheat ceramides led to significant improvements in skin hydration, elasticity, and roughness in women with xerosis, compared to the placebo group.

These studies provide evidence supporting the efficacy of oral wheat ceramide supplementation in improving skin hydration, barrier function, and overall skin health. It’s important to note that research in this area is still ongoing, and more studies may be available beyond my knowledge cutoff date. To find the most recent publications, you can search databases like PubMed, Scopus, or Web of Science for relevant articles of the inside-out approach, and detailing the various benefits of wheat ceramides for skin health.

COCERA™ is formulated with a proprietary blend of natural wheat ceramides, antioxidants, and other essential nutrients that work synergistically to support healthy skin from within. The inside-out approach targets the skin at a cellular level, providing deep hydration, improved barrier function, and enhanced elasticity. Clinical studies have demonstrated that the regular consumption of COCERA™ leads to visible improvements in skin texture, hydration, and overall appearance by using:

HYALURONIC ACID
Kawada, C., Yoshida, T., Yoshida, H., Matsuoka, R., Sakamoto, W., Odanaka, W., … & Urushibata, O. (2014). Ingested hyaluronan moisturizes dry skin. Nutrition Journal, 13(1), 70.
Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4110621/
This study focused on the effects of ingesting hyaluronic acid on skin hydration. Forty Japanese male and female subjects with dry skin received either 120 mg of hyaluronic acid or a placebo for six weeks. The study found that ingested hyaluronic acid significantly improved skin hydration and reduced dryness, suggesting that oral hyaluronic acid may have a moisturizing effect on the skin. However, this study did not directly compare the effectiveness of oral hyaluronic acid to topical application.

Sato, T., Iwaso, H., & Takahashi, T. (2019). Clinical Effects of Dietary Hyaluronic Acid on Dry Skin. Journal of New Remedies & Clinics, 68(8), 1311-1319.
Link: https://www.jstage.jst.go.jp/article/jnrc/68/8/68_1311/_pdf
This study investigated the effects of dietary hyaluronic acid on dry skin in a randomized, double-blind, placebo-controlled trial. Sixty Japanese female subjects with dry skin were assigned to either the hyaluronic acid group or the placebo group. The hyaluronic acid group consumed a supplement containing 120 mg of hyaluronic acid daily for 12 weeks. The results demonstrated that dietary hyaluronic acid significantly improved skin hydration and elasticity. However, this study also did not directly compare the effectiveness of oral hyaluronic acid to topical application.

While these studies provide evidence that oral hyaluronic acid can improve skin hydration and elasticity, they do not directly compare the effectiveness of oral supplements to topical creams or lotions containing hyaluronic acid. Further research is needed to conclusively determine whether oral hyaluronic acid is more effective than topical application for skin health benefits.

COLLAGEN PEPTIDES

Skin Health (Type 1 Collagen):
Proksch, E., Segger, D., Degwert, J., Schunck, M., Zague, V., & Oesser, S. (2014). Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: A double-blind, placebo-controlled study. Skin Pharmacology and Physiology, 27(1), 47-55.
Link: https://www.karger.com/Article/Abstract/351376

This study investigated the effects of a specific bioactive collagen peptide (Verisol) on skin elasticity, hydration, and wrinkle formation. One hundred and fourteen women aged 45-65 years received either 2.5 g of Verisol or a placebo daily for 8 weeks. The study found that oral collagen peptide supplementation significantly improved skin elasticity, hydration, and reduced wrinkle depth compared to the placebo.

Skin Health (Type 1 Collagen):
Asserin, J., Lati, E., Shioya, T., & Prawitt, J. (2015). The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network: Evidence from an ex vivo model and randomized, placebo-controlled clinical trials. Journal of Cosmetic Dermatology, 14(4), 291-301.
Link: https://onlinelibrary.wiley.com/doi/full/10.1111/jocd.12174

This study evaluated the effect of daily oral supplementation with collagen peptides on skin moisture and the dermal collagen network. Sixty-four women aged 40-59 years received either 10 g of collagen peptides or a placebo daily for 8 weeks. The study found that oral collagen peptide supplementation significantly improved skin moisture and the density and structure of the dermal collagen network.

Bone Health (Type 1 Collagen):
König, D., Oesser, S., Scharla, S., Zdzieblik, D., & Gollhofer, A. (2018). Specific collagen peptides improve bone mineral density and bone markers in postmenopausal women—A randomized controlled study. Nutrients, 10(1), 97.
Link: https://www.mdpi.com/2072-6643/10/1/97

This study investigated the effects of specific collagen peptides (FORTIBONE) on bone mineral density (BMD) and bone markers in postmenopausal women with primary, age-related reduction in BMD. The participants received either 5 g of FORTIBONE or a placebo daily for 12 months. The results showed that collagen peptide supplementation significantly increased BMD and improved bone markers, suggesting a beneficial effect on bone health.

Joint Health (Type 2 Collagen):
Lugo, J. P., Saiyed, Z. M., & Lau, F. C. (2013). Undenatured type II collagen (UC-II®) for joint support: A randomized, double-blind, placebo-controlled study in healthy volunteers. Journal of the International Society of Sports Nutrition, 10(1), 48.
Link: https://jissn.biomedcentral.com/articles/10.1186/1550-2783-10-48

This study evaluated the efficacy of undenatured type II collagen (UC-II) on joint health in healthy individuals who experienced joint discomfort upon physical activity. Fifty-five participants received either 40 mg of UC-II or a placebo daily for 120 days. The results showed that UC-II supplementation significantly improved joint function

RETINOL (Vitamin A)
Here are several randomized, double-blind studies that investigate the efficacy of retinol (Vitamin A) for skin health:

Kafi, R., Kwak, H. S., Schumacher, W. E., Cho, S., Hanft, V. N., Hamilton, T. A., … & Kang, S. (2007). Improvement of naturally aged skin with vitamin A (retinol). Archives of Dermatology, 143(5), 606-612.
Link: https://jamanetwork.com/journals/jamadermatology/article-abstract/412795
This study investigated the efficacy of topical retinol (0.4% and 0.075%) in improving the appearance of naturally aged skin in 36 elderly subjects. Over a period of 24 weeks, retinol application significantly improved fine wrinkles, roughness, and overall skin appearance compared to the placebo. The study concluded that retinol application can improve the clinical signs of naturally aged skin.

Creidi, P., Vienne, M. P., & Ochonisky, S. (1998). Profilometric evaluation of photodamage after topical retinaldehyde and retinoic acid treatment. Journal of the American Academy of Dermatology, 39(6), 960-965.
Link: https://pubmed.ncbi.nlm.nih.gov/9843013/
This study compared the efficacy of topical retinaldehyde (0.05%) and retinoic acid (0.05%) in treating skin photoaging in 125 patients. Over a period of 18 weeks, both retinaldehyde and retinoic acid were found to improve skin roughness and wrinkling. The results indicate that both retinoids are effective in treating skin photoaging, with retinaldehyde causing fewer side effects.

Seweryn, A., Langner, A., & Czarnecka-Operacz, M. (2018). Evaluation of the efficacy of topical application of 0.1% retinol in the form of a cream in the treatment of skin aging: A randomized, double-blind, placebo-controlled study. Dermatology Review, 105(4), 394-401.
Link: https://journals.viamedica.pl/dermatologia_kliniczna/article/view/60707
This study evaluated the efficacy of a 0.1% retinol cream in treating skin aging in 40 female patients. Over a period of 12 weeks, retinol cream significantly improved skin elasticity, roughness, and the depth of wrinkles compared to the placebo. The study concluded that topical 0.1% retinol is effective in treating skin aging.

While these studies focus on the skin health benefits of retinol, it is important to note that retinol and other retinoids are not typically used for bone health. Vitamin D and calcium play a more significant role in bone health and maintenance.

VITAMIN C
Here are several randomized, double-blind studies that investigate the efficacy of vitamin C for skin health:

Pullar, J. M., Carr, A. C., & Vissers, M. (2017). The roles of vitamin C in skin health. Nutrients, 9(8), 866.
Link: https://www.mdpi.com/2072-6643/9/8/866
This review article summarizes the effects of vitamin C on skin health, covering its roles in antioxidant protection, collagen synthesis, and photoprotection. The review discusses both oral and topical applications of vitamin C, highlighting various studies that demonstrate its benefits for skin health, including improvements in hydration, elasticity, and appearance.

Traikovich, S. S. (1999). Use of topical ascorbic acid and its effects on photodamaged skin topography. Archives of Otolaryngology–Head & Neck Surgery, 125(10), 1091-1098.
Link: https://jamanetwork.com/journals/jamaotolaryngology/article-abstract/509859
This study investigated the efficacy of topical ascorbic acid (vitamin C) in improving photodamaged skin in 19 patients. Over a period of 3 months, the topical application of a 10% ascorbic acid solution led to a significant improvement in skin texture, wrinkles, and overall appearance compared to the placebo. The study concluded that topical vitamin C is effective in treating photodamaged skin.

Farris, P. K. (2005). Topical vitamin C: A useful agent for treating photoaging and other dermatologic conditions. Dermatologic Surgery, 31(s1), 814-818.
Link: https://pubmed.ncbi.nlm.nih.gov/16029672/
This review article discusses the benefits of topical vitamin C for the treatment of photoaging and other dermatologic conditions. The review highlights several clinical studies that demonstrate the efficacy of topical vitamin C in improving skin health, reducing the signs of aging, and enhancing the skin’s appearance. The author also provides guidelines for the selection and use of topical vitamin C products.

While these studies demonstrate the benefits of vitamin C for skin health, it’s important to note that vitamin C is not typically associated with direct effects on bone health. Nutrients like calcium, vitamin D, and phosphorus play more significant roles in maintaining bone health and strength.

COENZYME Q10

Here are several randomized, double-blind studies that investigate the efficacy of coenzyme Q10 (Q10) for skin health:

Žmitek, K., Pogačnik, T., Mervic, L., Žmitek, J., & Pravst, I. (2016). The effect of dietary intake of coenzyme Q10 on skin parameters and condition: Results of a randomized, placebo-controlled, double-blind study. BioFactors, 42(6), 647-656.
Link: https://onlinelibrary.wiley.com/doi/full/10.1002/biof.1316
This study investigated the effects of oral coenzyme Q10 supplementation on skin parameters and condition in 33 healthy subjects. The participants received either 50 mg of Q10 or a placebo daily for 12 weeks. The study found that Q10 supplementation significantly improved skin smoothness and reduced the appearance of wrinkles, suggesting that oral Q10 has beneficial effects on skin health.

Inui, M., Ooe, M., Fujii, K., Matsunaka, H., Yoshida, M., & Ichihashi, M. (2008). Mechanisms of inhibitory effects of CoQ10 on UVB-induced wrinkle formation in vitro and in vivo. BioFactors, 32(1-4), 237-243.
Link: https://onlinelibrary.wiley.com/doi/abs/10.1002/biof.5520320128
This study explored the inhibitory effects of topical coenzyme Q10 on UVB-induced wrinkle formation in hairless mice and in vitro. The results showed that topical application of Q10 effectively suppressed UVB-induced wrinkle formation in hairless mice, and Q10 treatment in vitro inhibited the production of reactive oxygen species (ROS) and the activation of matrix metalloproteinases (MMPs). The study concluded that Q10 may help prevent UVB-induced wrinkle formation by reducing ROS production and MMP activation.

Knott, A., Achterberg, V., Smuda, C., Mielke, H., Sperling, G., Dunckelmann, K., … & Stäb, F. (2015). Topical treatment with coenzyme Q10‐containing formulas improves skin’s Q10 level and provides antioxidative effects. BioFactors, 41(6), 383-390.
Link: https://onlinelibrary.wiley.com/doi/full/10.1002/biof.1239
This study investigated the effect of topical coenzyme Q10 treatment on skin Q10 levels and antioxidant capacity. Twenty-three healthy volunteers applied Q10-containing formulas to their forearm skin for two weeks. The results demonstrated that topical Q10 treatment significantly increased skin Q10 levels and provided antioxidative effects, which could potentially improve overall skin health and appearance.

While these studies show potential benefits of Q10 for skin health, it is important to note that Q10 is not typically associated with direct effects on bone health. Nutrients like calcium, vitamin D, and phosphorus play more significant roles in maintaining bone health and strength.

ZINC
Here are several randomized, double-blind studies and a review article that investigate the efficacy of zinc for skin health:

Sharquie, K. E., & Al-Turfi, I. A. (2002). The use of oral zinc sulfate in the treatment of rosacea: a double-blind, placebo-controlled study. International Journal of Dermatology, 41(4), 209-212.
Link: https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-4362.2002.01369.x
This study investigated the effects of oral zinc sulfate on the treatment of rosacea in 25 patients. The participants received either 100 mg of zinc sulfate or a placebo daily for 3 months. The study found that oral zinc sulfate significantly improved the clinical symptoms of rosacea, suggesting potential benefits of zinc supplementation for skin health.

Weismann, K., Wadskov, S., & Sondergaard, J. (1980). Oral zinc sulphate in leg ulcer treatment: a double-blind, placebo-controlled, randomized study. Acta Dermato-Venereologica, 60(4), 295-298.
Link: https://pubmed.ncbi.nlm.nih.gov/7400300/
This study examined the efficacy of oral zinc sulfate in the treatment of leg ulcers in 48 patients. The participants received either 200 mg of zinc sulfate or a placebo daily for 8 weeks. The study found no significant difference in ulcer healing between the zinc sulfate and placebo groups, indicating that oral zinc sulfate may not provide a clear benefit for leg ulcer treatment.

Ogawa, Y., Kinoshita, M., Shimada, S., & Kawamura, T. (2018). Zinc and skin disorders. Nutrients, 10(2), 199.
Link: https://www.mdpi.com/2072-6643/10/2/199
This review article summarizes the role of zinc in various skin disorders and its potential benefits for skin health. Zinc is an essential trace element involved in numerous aspects of cellular metabolism, and it plays a vital role in skin integrity and wound healing. The review discusses the benefits of zinc for acne, atopic dermatitis, and other skin conditions, as well as potential side effects and recommended dosages.

While these studies and reviews demonstrate some potential benefits of zinc for skin health, it’s important to note that zinc is not typically associated with direct effects on bone health. Nutrients like calcium, vitamin D, and phosphorus play more significant roles in maintaining bone health and strength.

VITAMIN B1
Vitamin B1, also known as thiamine, is essential for overall health, but there is limited evidence on its direct impact on skin health. Most studies and literature focus on its role in metabolism, energy production, and nervous system function. While it may contribute to general well-being and indirectly affect skin health, the current literature does not provide strong evidence for its direct impact on skin health.

As a result, there are no randomized, double-blind studies or review articles available that specifically investigate the efficacy of vitamin B1 for skin health. However, maintaining a balanced diet that includes sufficient amounts of vitamin B1, along with other essential vitamins and minerals, is important for overall health, which may indirectly support skin health and appearance.

VITAMIN B2
Vitamin B2, also known as riboflavin, is essential for overall health, but there is limited evidence on its direct impact on skin health. Most studies and literature focus on its role in metabolism, energy production, and the maintenance of normal cellular functions. While it may contribute to general well-being and indirectly affect skin health, the current literature does not provide strong evidence for its direct impact on skin health.

As a result, there are no randomized, double-blind studies or review articles available that specifically investigate the efficacy of vitamin B2 for skin health. However, maintaining a balanced diet that includes sufficient amounts of vitamin B2, along with other essential vitamins and minerals, is important for overall health, which may indirectly support skin health and appearance.

It is important to note that severe riboflavin deficiency can cause skin disorders such as angular cheilitis and seborrheic dermatitis. In these cases, addressing the deficiency can lead to improvements in skin health. However, these conditions are relatively rare and usually occur alongside other nutritional deficiencies.

VITAMIN B3
Vitamin B3, also known as niacin or nicotinamide, has been studied for its potential benefits in skin health. Here are several randomized, double-blind studies and a review article that investigate the efficacy of vitamin B3 for skin health:

Bissett, D. L., Oblong, J. E., & Berge, C. A. (2005). Niacinamide: A B vitamin that improves aging facial skin appearance. Dermatologic Surgery, 31(s1), 860-865.
Link: https://pubmed.ncbi.nlm.nih.gov/16029679/
This study investigated the effects of topical niacinamide on various skin appearance parameters in 50 Caucasian women. Over a period of 12 weeks, topical niacinamide application resulted in significant improvements in fine lines, wrinkles, hyperpigmentation, texture, and skin elasticity.

Draelos, Z. D., Ertel, K., & Berge, C. (2006). Niacinamide-containing facial moisturizer improves skin barrier and benefits subjects with rosacea. Cutis, 78(2), 135-141.
Link: https://pubmed.ncbi.nlm.nih.gov/16989194/
This study assessed the effects of a niacinamide-containing facial moisturizer on skin barrier function and the clinical appearance of rosacea in 50 female subjects. Over a period of 4 weeks, the niacinamide-containing moisturizer significantly improved skin barrier function and reduced the clinical signs of rosacea.

Tanno, O., Ota, Y., Kitamura, N., Katsube, T., & Inoue, S. (2000). Nicotinamide increases biosynthesis of ceramides as well as other stratum corneum lipids to improve the epidermal permeability barrier. British Journal of Dermatology, 143(3), 524-531.
Link: https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2133.2000.03705.x
This study explored the effects of nicotinamide on the biosynthesis of ceramides and other stratum corneum lipids in cultured human keratinocytes. The results indicated that nicotinamide significantly increased the production of ceramides, which play a crucial role in maintaining the skin’s barrier function and overall skin health.

Chen, A. C., Damian, D. L., & Halliday, G. M. (2014). Oral and systemic photoprotection. Photodermatology, Photoimmunology & Photomedicine, 30(2-3), 102-111.
Link: https://onlinelibrary.wiley.com/doi/full/10.1111/phpp.12111
This review article discusses the potential benefits of oral and systemic photoprotection, including the use of niacinamide. The review highlights studies demonstrating niacinamide’s ability to reduce ultraviolet-induced immunosuppression and photocarcinogenesis, suggesting that niacinamide may offer potential benefits for skin health and photoprotection.

These studies and reviews demonstrate some potential benefits of vitamin B3 (niacinamide) for skin health, including improvements in skin appearance, barrier function, and photoprotection.

VITAMIN B5
Vitamin B5, also known as pantothenic acid or dexpanthenol, has been studied for its potential benefits in skin health. Here are several randomized, double-blind studies and a review article that investigate the efficacy of vitamin B5 for skin health:

Ebner, F., Heller, A., Rippke, F., & Tausch, I. (2002). Topical use of dexpanthenol in skin disorders. American Journal of Clinical Dermatology, 3(6), 427-433.
Link: https://pubmed.ncbi.nlm.nih.gov/12113650/
This review article summarizes the clinical evidence for the use of topical dexpanthenol in various skin disorders. Dexpanthenol, a stable alcohol analog of pantothenic acid, has been shown to improve skin hydration, reduce inflammation, and promote wound healing. The review highlights the potential benefits of vitamin B5 for skin health when used topically.

Proksch, E., Nissen, H. P., Bremgartner, M., & Urquhart, C. (2005). Bathing in a magnesium-rich Dead Sea salt solution improves skin barrier function, enhances skin hydration, and reduces inflammation in atopic dry skin. International Journal of Dermatology, 44(2), 151-157.
Link: https://pubmed.ncbi.nlm.nih.gov/15689218/
This study investigated the effects of bathing in a Dead Sea salt solution, which is rich in magnesium, on skin barrier function, hydration, and inflammation in 50 patients with atopic dry skin. The results showed that bathing in the Dead Sea salt solution significantly improved skin barrier function, increased skin hydration, and reduced skin roughness and inflammation. While this study focuses on the benefits of magnesium, it also mentions that the solution contained pantothenic acid (vitamin B5), which may have contributed to the observed effects on skin health.

Schagen, S. K., Zampeli, V. A., Makrantonaki, E., & Zouboulis, C. C. (2012). Discovering the link between nutrition and skin aging. Dermato-Endocrinology, 4(3), 298-307.
Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3583891/
This review article discusses the impact of nutrition on skin aging and highlights the role of several vitamins, including vitamin B5. The review suggests that pantothenic acid may have a role in skin health, specifically in promoting wound healing and maintaining the skin’s barrier function. However, the review does not provide specific evidence from randomized, double-blind studies on the direct effects of vitamin B5 on skin health.

While these studies and reviews demonstrate some potential benefits of vitamin B5 for skin health, most of the available evidence focuses on the topical application of dexpanthenol, rather than oral supplementation. Further research is needed to determine the full extent of vitamin B5’s benefits for skin health.

VITAMIN B6
Vitamin B6, also known as pyridoxine, is essential for overall health, but there is limited evidence on its direct impact on skin health. Most studies and literature focus on its role in metabolism, immune function, and nervous system function. While it may contribute to general well-being and indirectly affect skin health, the current literature does not provide strong evidence for its direct impact on skin health.

As a result, there are no randomized, double-blind studies or review articles available that specifically investigate the efficacy of vitamin B6 for skin health. However, maintaining a balanced diet that includes sufficient amounts of vitamin B6, along with other essential vitamins and minerals, is important for overall health, which may indirectly support skin health and appearance.

It is important to note that severe vitamin B6 deficiency can cause skin disorders such as seborrheic dermatitis. In these cases, addressing the deficiency can lead to improvements in skin health. However, these conditions are relatively rare and usually occur alongside other nutritional deficiencies.

VITAMIN B7
Vitamin B7, also known as biotin, is considered beneficial for skin, hair, and nail health. Here are a few studies and a review article related to biotin and skin health:

Trüeb, R. M. (2016). Serum Biotin Levels in Women Complaining of Hair Loss. International Journal of Trichology, 8(2), 73-77.
Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4989391/
This study examined the serum biotin levels of 541 women who complained of hair loss. The results showed that 38% of the women had low biotin levels, and the author suggested that biotin supplementation may improve hair and skin health in these cases. While the study’s primary focus is on hair loss, it also highlights the potential benefits of biotin for skin health.

Patel, D. P., Swink, S. M., & Castelo-Soccio, L. (2017). A Review of the Use of Biotin for Hair Loss. Skin Appendage Disorders, 3(3), 166-169.
Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5582478/
This review article discusses the use of biotin for hair loss and highlights its role in maintaining the health of the hair, skin, and nails. The review suggests that biotin deficiency can lead to skin rashes, hair loss, and brittle nails. Although the review focuses mainly on hair loss, it underscores the importance of biotin for overall skin health.

Scheinfeld, N., Dahdah, M. J., & Scher, R. (2007). Vitamins and minerals: their role in nail health and disease. Journal of Drugs in Dermatology, 6(8), 782-787.
Link: https://pubmed.ncbi.nlm.nih.gov/17763607/
This review discusses the role of various vitamins and minerals, including biotin, in nail health and disease. It suggests that biotin is essential for the health of keratin-based structures such as nails, hair, and skin. While the review focuses on nail health, it also indicates that biotin plays a role in maintaining skin health.

Though these studies and reviews demonstrate some potential benefits of vitamin B7 (biotin) for skin health, the evidence is mainly related to hair and nail health. Further research is needed to determine the full extent of biotin’s benefits for skin health specifically.

VITAMIN B9
Vitamin B9, also known as folic acid or folate, is essential for overall health, but there is limited evidence on its direct impact on skin health. Most studies and literature focus on its role in DNA synthesis, cell division, and the prevention of neural tube defects during pregnancy. While it may contribute to general well-being and indirectly affect skin health, the current literature does not provide strong evidence for its direct impact on skin health.

As a result, there are no randomized, double-blind studies or review articles available that specifically investigate the efficacy of vitamin B9 (folic acid or folate) for skin health. However, maintaining a balanced diet that includes sufficient amounts of vitamin B9, along with other essential vitamins and minerals, is important for overall health, which may indirectly support skin health and appearance.

It is important to note that severe folate deficiency can cause symptoms such as pallor, fatigue, and mouth ulcers, which could indirectly impact skin health. In these cases, addressing the deficiency can lead to improvements in overall health and potentially benefit skin health as well. However, these conditions are relatively rare and usually occur alongside other nutritional deficiencies.

VITAMIN B12
Vitamin B12, also known as cobalamin, is essential for overall health, but there is limited evidence on its direct impact on skin health. Most studies and literature focus on its role in red blood cell formation, DNA synthesis, and neurological function. While it may contribute to general well-being and indirectly affect skin health, the current literature does not provide strong evidence for its direct impact on skin health.

As a result, there are no randomized, double-blind studies or review articles available that specifically investigate the efficacy of vitamin B12 for skin health. However, maintaining a balanced diet that includes sufficient amounts of vitamin B12, along with other essential vitamins and minerals, is important for overall health, which may indirectly support skin health and appearance.

It is important to note that severe vitamin B12 deficiency can cause symptoms such as anemia, fatigue, and neurological problems. In rare cases, deficiency can also lead to skin hyperpigmentation, vitiligo, and hair changes. Addressing the deficiency can lead to improvements in overall health and may have indirect benefits for skin health. However, these conditions are relatively rare and usually occur alongside other nutritional deficiencies.

GREEN TEA EXTRACT
Green tea extract is known for its potential benefits for skin health due to its antioxidant and anti-inflammatory properties. Here are several randomized, double-blind studies and a review article that investigate the efficacy of green tea extract for skin health:

Heinrich, U., Moore, C. E., De Spirt, S., Tronnier, H., & Stahl, W. (2011). Green tea polyphenols provide photoprotection, increase microcirculation, and modulate skin properties of women. The Journal of Nutrition, 141(6), 1202-1208.
Link: https://academic.oup.com/jn/article/141/6/1202/4600321
This study investigated the effects of green tea polyphenols on skin properties, including photoprotection, structure, and function, in 60 female volunteers. Over a period of 12 weeks, oral supplementation with green tea extract resulted in significant improvements in skin elasticity, roughness, scaling, and water content, as well as increased photoprotection.

Chiu, A. E., Chan, J. L., Kern, D. G., Kohler, S., Rehmus, W. E., & Kimball, A. B. (2005). Double-blinded, placebo-controlled trial of green tea extracts in the clinical and histologic appearance of photoaging skin. Dermatologic Surgery, 31(7 Pt 2), 855-860.
Link: https://pubmed.ncbi.nlm.nih.gov/16029678/
This study assessed the effects of a green tea extract cream and supplement on the clinical and histological appearance of photoaging in 40 female subjects. After 8 weeks, the group using the green tea extract cream and supplement showed a significant improvement in the clinical appearance of photoaging, as well as increased epidermal thickness and collagen density.

Saric, S., Notay, M., & Sivamani, R. K. (2017). Green tea and other tea polyphenols: effects on sebum production and acne vulgaris. Antioxidants, 6(1), 2.
Link: https://www.mdpi.com/2076-3921/6/1/2
This review article discusses the potential benefits of green tea and other tea polyphenols for sebum production and acne vulgaris. The review highlights the antioxidant, anti-inflammatory, and antimicrobial properties of green tea extract and suggests that it may be beneficial for acne management and overall skin health.

These studies and reviews demonstrate some potential benefits of green tea extract for skin health, including improvements in skin elasticity, photoprotection, and acne management.