Abstract：
OBJECTIVE: The effect of vitamin D on skin carcinogenesis is unclear. Vitamin D derivatives may protect against ultraviolet radiation (UVR)-induced DNA damage, immune suppression, and skin carcinogenesis. However, some epidemiological studies have reported an increased incidence of skin cancer associated with high serum vitamin D levels. We investigated the effect of vitamin D supplementation on serum, skin, and tumor vitamin D levels and on skin cancer development in hairless immunocompetent mice.
METHODS: Female C3.Cg-Hrhr/TifBomTac immunocompetent mice (n=125) were randomly separated into five groups. Two groups received a high vitamin D3 diet (4.5 μg/day/mouse). One group received a medium vitamin D3 diet (2.3 μg/day/mouse). Two groups received a standard diet (0.045 μg/day/mouse). Three standard erythema doses of UVR were given three times per week to three groups.
RESULTS: Animals on a high vitamin D3 diet had ~150-fold higher serum vitamin D3 levels (p=0.00016) and 3-fold higher serum 25-hydroxyvitamin D3 [25(OH)D3] levels (p=0.00016) than those on a standard diet. For mice on the medium vitamin D3 diet, serum vitamin D3 and 25(OH)D3 levels were 18-fold and 2.3-fold higher than for the standard diet, respectively (p=0.00016). All UVR-exposed mice developed tumors. Vitamin D3 levels were lower in the tumor than the skin (p<0.0001). High and medium supplementation with vitamin D3 did not affect tumor development (p>0.05).
CONCLUSIONS: In mice, vitamin D levels in the serum, skin, and tumors were augmented by supplementation, but this did not affect the development of UVR-induced skin tumors.
METHODS: Female C3.Cg-Hrhr/TifBomTac immunocompetent mice (n=125) were randomly separated into five groups. Two groups received a high vitamin D3 diet (4.5 μg/day/mouse). One group received a medium vitamin D3 diet (2.3 μg/day/mouse). Two groups received a standard diet (0.045 μg/day/mouse). Three standard erythema doses of UVR were given three times per week to three groups.
RESULTS: Animals on a high vitamin D3 diet had ~150-fold higher serum vitamin D3 levels (p=0.00016) and 3-fold higher serum 25-hydroxyvitamin D3 [25(OH)D3] levels (p=0.00016) than those on a standard diet. For mice on the medium vitamin D3 diet, serum vitamin D3 and 25(OH)D3 levels were 18-fold and 2.3-fold higher than for the standard diet, respectively (p=0.00016). All UVR-exposed mice developed tumors. Vitamin D3 levels were lower in the tumor than the skin (p<0.0001). High and medium supplementation with vitamin D3 did not affect tumor development (p>0.05).
CONCLUSIONS: In mice, vitamin D levels in the serum, skin, and tumors were augmented by supplementation, but this did not affect the development of UVR-induced skin tumors.
摘要：
目的：维生素D对皮肤癌变的影响尚不清楚。维生素D衍生物可以防止紫外线辐射（UVR）诱导的DNA损伤，免疫抑制，和皮肤癌。然而,一些流行病学研究报道,与高血清维生素D水平相关的皮肤癌发病率增加.我们调查了补充维生素D对血清的影响，皮肤,和肿瘤维生素D水平以及无毛免疫活性小鼠皮肤癌的发展。
方法：女性C3。将Cg-Hrhr/TifBomTac免疫活性小鼠（n=125）随机分为五组。两组接受高维生素D3饮食(4.5μg/天/小鼠)。一组接受中等维生素D3饮食(2.3μg/天/小鼠)。两组接受标准饮食(0.045μg/天/小鼠)。三组每周三次给予标准红斑剂量的UVR。
结果：高维生素D3饮食的动物血清维生素D3水平（p=0.00016）和血清25-羟维生素D3[25（OH）D3]水平（p=0.00016）比标准饮食的动物高150倍。对于中等维生素D3饮食的小鼠，血清维生素D3和25（OH）D3水平比标准饮食高18倍和2.3倍，分别（p=0.00016）。所有暴露于UVR的小鼠发展成肿瘤。肿瘤中的维生素D3水平低于皮肤(p<0.0001)。高、中补充维生素D3不影响肿瘤发展(p>0.05)。
结论：在小鼠中，血清中的维生素D水平,皮肤,肿瘤通过补充增加，但这并不影响UVR诱导的皮肤肿瘤的发展。
方法：女性C3。将Cg-Hrhr/TifBomTac免疫活性小鼠（n=125）随机分为五组。两组接受高维生素D3饮食(4.5μg/天/小鼠)。一组接受中等维生素D3饮食(2.3μg/天/小鼠)。两组接受标准饮食(0.045μg/天/小鼠)。三组每周三次给予标准红斑剂量的UVR。
结果：高维生素D3饮食的动物血清维生素D3水平（p=0.00016）和血清25-羟维生素D3[25（OH）D3]水平（p=0.00016）比标准饮食的动物高150倍。对于中等维生素D3饮食的小鼠，血清维生素D3和25（OH）D3水平比标准饮食高18倍和2.3倍，分别（p=0.00016）。所有暴露于UVR的小鼠发展成肿瘤。肿瘤中的维生素D3水平低于皮肤(p<0.0001)。高、中补充维生素D3不影响肿瘤发展(p>0.05)。
结论：在小鼠中，血清中的维生素D水平,皮肤,肿瘤通过补充增加，但这并不影响UVR诱导的皮肤肿瘤的发展。
