As with conventional medical treatments for repigmentation, unconventional treatments combine exposure to UVA rays, UVB rays or the sun with a substance taken orally or topically.

 Khelline (Ammi visnaga). From the fruit of the Mediterranean plant called khella, khellin is extracted, a photosensitizing substance chemically similar to psoralen, used for PUVA phototherapy. Khellin has been tested topically and orally in several small clinical trials²⁶. A study carried out in 2004⁴ even showed that khellin had an efficacy comparable to that of psoralen in the context of UVA phototherapy. In addition, the use of khellin instead of psoralen to potentiate UVA rays may cause fewer side effects, especially when applied topically. However, clinical trials have been conducted on a small number of patients and have given conflicting results.^5-7 . In 2008, a committee of English experts²⁷ therefore concluded that there was insufficient evidence to recommend the use of khellin as a replacement for psoralen.

Dosage

Khellin has been tested orally and topically. Its dosage varies depending on the case, and treatment should be planned with a dermatologist.

 Polypodium leucotomos. Other photosensitizing plants have been tested in association with phototherapy²⁶, in particular an extract from Polypodium leucotomos, a fern from Central America. A 2007 randomized trial on 50 people with vitiligo evaluated the effectiveness of P. leucotomos (250 mg orally) taken 3 times daily compared to placebo. The patients were subjected to narrow-spectrum UVB phototherapy sessions twice a week for 2 weeks. Repigmentation was more satisfactory in the group receiving the P. leucotomos²⁸.

 Phenylalanine. Phenylalanine is an amino acid (elementary molecule of proteins) essential for the production of melanin, the dark pigment of the skin. It has been tested in combination with UVA rays or sun exposure for its effect on repigmentation. Two preliminary clinical studies carried out in 1985 and 1989 indicate that oral phenylalanine, combined with exposure to UVA rays, is effective for the treatment of vitiligo.^8,9. Another study involving 7 subjects (100 mg of phenylalanine per kg per day), however, obtained no repigmentation.¹⁰. The only double-blind clinical study involved 32 subjects who, for 6 months, received treatment with phenylalanine and UVA rays every day. At best, a 60% repigmentation of vitiligo spots was achieved¹¹. The optimal dosage used was less than 50 mg per kg of body weight per day. In 2002, a pilot study concluded that its topical use (a gel containing 10% phenylalanine) was also effective¹². An analysis published in 2008²⁶ however regrets the poor methodological quality of the various studies and suggests that other research, in the longer term and on a larger scale, be carried out.

 Ginkgo biloba. In 2003, a double-blind, placebo-controlled trial showed the effectiveness of ginkgo biloba in slowing the progression of vitiligo. In this study, 47 adults with active vitiligo received 40 mg, 3 times a day, of a ginkgo biloba extract or a placebo for 6 months. Ginkgo extract has been used to stop the progression of vitiligo in all individuals with vitiligo of the hands or face, and in 25% to 30% of those with vitiligo affecting other parts of the body³⁰. Several patients have even observed repigmentation of the spots. While promising, the results of this study have yet to be confirmed by other larger clinical trials.

 Folic acid and vitamin B12. According to some authors, some people with vitiligo have lower than normal blood levels of folic acid (vitamin B9) and vitamin B12. In naturotherapy, it is believed that vitiligo can be caused by nutritional deficiencies attributable to a diet composed of denatured foods poor in nutrients (foods made from bleached flour, white sugar, etc.). Surprisingly, cases of total re-pigmentation have been reported after 3-6 months of supplementation with these vitamins and exposure to the sun.^13,14. However, a study conducted in 2002 concluded that the combination of vitamins and UVB rays is no more effective than UVB rays alone in treating vitiligo.¹⁵, which was confirmed by an analysis of studies in 2008²⁶.

 Vitamin D (topically applied). A synthetic derivative of vitamin D, calcipotriol, could potentiate the effect of photochemotherapy treatments which combine UVA rays with psoralen (the PUVA method). Vitamin D is essential for calcium metabolism and is present in the development of skin cells. Five studies carried out between 1998 and 2003 on a small number of patients gave mixed results²⁷. Two of them, carried out on a total of 46 people with vitiligo, showed that the application of a calcipotriol cream (50 µg / g) before the PUVA treatment generates greater repigmentation than the PUVA treatment alone.^16,17. However, in 2003, a controlled study found no additional efficacy in the 22 subjects who used calcitopriol cream before their PUVA treatments.¹⁹. In 2006, a study showed that applying calcipotriol cream also did not increase the effectiveness of UVB treatment.²⁹. It is therefore not currently recommended to use this product²⁷.