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发表于 2011-12-1 01:22:51
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"龜俠: 鈣粉吸收過量如果能正常排出就ok,但如果不能排出就會形成鈣積聚，影響腎臟至結石，後果可大可小，所以鈣粉每星期有正常供應就可以la !"
龜俠哥哥, 之前有個讀生化(Bio-Chem)既大學生龜友已經開過POST講得好祥細, 如果冇 激活型 維生素D (calcitriol), 龜的小腸根本無法吸收鈣入血!!!!!!!!!!!!!!!!!!!!!!
而且激活型維生素D (calcitriol) 會由龜身體自我調節!! 根本不會過量吸收鈣入血!! 龜只會吸收鈣量過少, 而不會過量吸收鈣入血!! 如果入血的鈣量不會多, 何來 "形成鈣積聚，影響腎臟至結石"?? 荒謬!!! 多餘的鈣粉只會由大便排出!!! 而且Zoomed精細既鈣粉Calcium Carbonate係完全水溶性, 不會形成便秘或硬塊.
激活型維生素D (calcitriol) 會在體內累積, 但鈣不會累積, 所以曬一次太陽, 足夠一星期既激活型維生素D (calcitriol)!
呢編係外國既文章:
Vitamin D3 synthesis, as most are aware, occurs in the skin with exposure to UVB and, as most are probably unaware, is a two-step process that also requires IR (infrared or heat). The first step converts a starting compound, 7-dehydrocholesterol, to preVitamin D3 utilizing the energy input of UVB in a rather fast reaction. The second step, the conversion of preVitamin D3 to Vitamin D3 is a slower reaction which relies on IR to provide the energy. This is much of the reason that reptiles bask.
Vit D3 synthesis: 7DHC → preVit D3 → Vit D3
Once the intake of the nutrients has occurred, the next step is the conversion of these nutrients into compounds which are usable by the organism. In the case of calcium, it is absorbed in the small intestine and transported by the circulatory system under the control of calcitriol. Calcitriol is the active Vitamin D in calcium regulation/utilization and is the product of a two-step Vitamin D3 metabolism process.
Vit D3 metabolism: Vit D3 → calcidiol → calcitriol
Vitamin D3 probably does not remain in high concentrations in the circulatory system but an intermediate metabolite (the step-one result), calcidiol, is likely used as a storage mechanism. Alternate metabolic conversions occur to prevent the overabundance of preVitamin D3 and Vitamin D3, some of which are reversible thereby extending the potential availability of the functional components. In most healthy organisms, this Vitamin D3 supply pool provides several days to several weeks of available source components.
自然界既龜係咁食鈣既:
[youtube]oA44ihioh8k[/youtube]
食渦牛補鈣及動物蛋白:
[youtube]TngzYM9tMZ0[/youtube]
我D龜係咁食既: (外國龜網話完全冇問題,好多人都係咁做,分開餵)
[youtube]1r3hkTShXZ4[/youtube] |
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