a vitamin d derivative to be administered to the vaginal cavity of a domestic mammal in the present invention includes a vitamin d derivative represented by the following general formula ( 1 ): wherein r 1 and r 2 each represent a hydrogen atom or r 1 and r 2 together may form a double bond ; r 3 represents a hydrogen atom or a methyl group ; and r 4 represents a hydrogen atom or a hydroxyl group . a concrete example of the vitamin d derivative represented by the above general formula ( 1 ) includes a calciferol derivative ( vitamin d 2 derivative ) wherein r 1 and r 2 together form a double bond and r 3 represents a methyl group or a cholecalciferol derivative ( vitamin d 3 derivative ) wherein r 1 , r 2 , and r 3 each represent a hydrogen atom . of those vitamin d 2 and d 3 derivatives , 1α - hydroxyvitamin d and / or 1 , 25 - dihydroxyvitamin d derivatives are preferred . a typical example thereof includes 1α - hydroxyvitamin d 2 , 1α - hydroxyvitamin d 3 , or 1α , 25 - dihydroxyvitamin d 3 . the vitamin d derivative is administered to a vaginal cavity using an intravaginal insert containing the vitamin d derivative . the form of the intravaginal insert ( delivery type ) that can be used is , for example , a gel , a tablet , a microsphere , and cidr , which are generally used . the absorption of the vitamin d derivative from the vaginal mucous membrane can be confirmed by observing changes in the vitamin d derivative administered to the vaginal cavity and several types of minerals ( calcium ( ca ), inorganic phosphorus ( ip ), and magnesium ( mg )). for example , the absorption can be confirmed by intravaginally administering 1 , 25 -( oh ) 2 d 3 dissolved in ethanol at a dose of approximately 1 μg per kg of body weight to the vaginal cavity of a cow and comparing the cow with a control to which ethanol is administered . in the cow to which 1 , 25 -( oh ) 2 d 3 is administered , the value of 1 , 25 -( oh ) 2 d 3 in plasma changes and the values of ca , ip , and mg in plasma change . the absorption of 1 , 25 -( oh ) 2 d 3 can be confirmed by observing the changes in the value of 1 , 25 -( oh ) 2 d 3 in plasma . fig1 shows the shift with time of a 1 , 25 - dihydroxyvitamin d 3 ( 1 , 25 -( oh ) 2 d 3 ) concentration in blood for each test cow ( cow a or cow b ) by the intravaginal administration of 1α - vd 3 in example 1 . fig2 shows the shift with time of a calcium ( ca ) concentration in blood for each test cow ( cow a or cow b ) by the intravaginal administration of 1α - vd 3 in example 1 . fig3 shows the shift with time of an inorganic phosphorus ( ip ) concentration in blood for each test cow ( cow a or cow b ) by the intravaginal administration of 1α - vd 3 in example 1 . fig4 shows the shift with time of a magnesium ( mg ) concentration in blood for each test cow ( cow a or cow b ) by the intravaginal administration of 1α - vd 3 in example 1 . fig5 shows the shift with time of a vitamin a ( vita ) concentration in blood for each test cow ( cow a or cow b ) by the intravaginal administration of vitad 3 e in comparative example 1 . fig6 shows the shift with time of a vitamin e ( vite ) concentration in blood for each test cow ( cow a or cow b ) by the intravaginal administration of vitad 3 e in comparative example 1 . fig7 shows the shift with time of a 25 - hydroxyvitamin d 3 ( 25 - ohd 3 ) concentration in blood for each test cow ( cow a or cow b ) by the intravaginal administration of vitad 3 e in comparative example 1 . fig8 shows the shift with time of a 1 , 25 -( oh ) 2 d 3 concentration in plasma for raised cows to which 1 , 25 -( oh ) 2 d 3 ( n = 5 ; ●) and ethanol ( n = 1 ; ▪) are intravaginally administered in example 2 . fig9 shows the shift with time of mineral ( ca , ip , and mg ) concentrations in plasma for raised cows to which 1 , 25 -( oh ) 2 d 3 ( n = 5 ; ●) and ethanol ( n = 1 ; ▪) are intravaginally administered in example 2 . fig1 shows the shift with time of a 1 , 25 -( oh ) 2 d 3 concentration in plasma for raised cows to which 1 , 25 -( oh ) 2 d 3 is intravaginally administered in example 3 . however , in fig1 , “ iv ” denotes intravenous administration ( ditto with fig1 to fig1 ). fig1 shows the shift with time of a calcium concentration in plasma for raised cows to which 1 , 25 -( oh ) 2 d 3 is intravaginally administered in example 3 . fig1 shows the shift with time of an ip concentration in plasma for raised cows to which 1 , 25 -( oh ) 2 d 3 is intravaginally administered in example 3 . fig1 shows the shift with time of a mg concentration in plasma for raised cows to which 1 , 25 -( oh ) 2 d 3 is intravaginally administered in example 3 . fig1 shows the shift with time of a ca / creatinine ( cre ) concentration in urine for raised cows to which 1 , 25 -( oh ) 2 d 3 is intravaginally administered in example 3 . fig1 shows the shift with time of an ip / creatinine ( cre ) concentration in urine for raised cows to which 1 , 25 -( oh ) 2 d 3 is intravaginally administered in example 3 . fig1 shows the shift with time of a mg / creatinine ( cre ) concentration in urine for raised cows to which 1 , 25 -( oh ) 2 d 3 is intravaginally administered in example 3 . hereinafter , the present invention will further be described with reference to examples and comparative example . however , the present invention is not intended to be limited to them by any means . in the examples described below , a 1 , 25 -( oh ) 2 d 3 concentration in plasma was determined using a radioimmunoassay kit ( 1 , 25 -( oh ) 2 d ria kit , immunodiagnostic systems limited , uk ). the ca concentrations , inorganic phosphorus ( ip ) concentrations , and magnesium ( mg ) concentrations in plasma and urine were determined by orthocresolphthalein complexone ( o - cpc ), molybdenum ( mo ), and xylidyl blue methods , respectively . a creatinine concentration in urine was determined by a jaffe method . calcium ( ca ), inorganic phosphorus ( ip ), and magnesium ( mg ) concentrations in urine were indicated in the ratios relative to creatinine ( cre ) ( ca / cre , ip / cre , and mg / cre , respectively ). biochemical changes in blood were observed by administering 1α - hydroxyvitamin d 3 to the vaginal cavities of cows . test animals used were two holstein dairy cows ( cow a and cow b ) described below . during a test period , the cows were raised by the free grazing of hay ( free water drinking ) in a field paddock as well as feeding with 2 kg / day of formula feed ( 64 . 1 % tdn , 13 . 6 % cp , 0 . 2 % ca , 0 . 09 % mg , and 1 . 39 % k in dm ). 1α - hydroxyvitamin d 3 ( 1α - vd 3 ; manufactured by nisshin pharma co ., ltd ., powder ). 1 . control test : intravaginal administration of 4 ml of 20 % ethanol ( for 1 week ); and 2 . 1α - vd 3 test : intravaginal administration of 1 μg / kg ( by body weight ) of 1α - vd 3 dissolved in 4 ml of 20 % ethanol ( for 2 weeks ). the above - described reagent was prepared on ice water and then administered , with a 10 - ml plastic syringe , to a deep region in the vagina of the test cows previously allowed to urinate and vulva skin was immediately closed with an instant adhesive . in each test , blood was collected immediately before administration ( 0 hour ) and at 0 . 5 , 1 , 2 , 3 , 6 , 12 , 24 , 48 , and 72 hours ( hrs ) after administration . the biochemical examination of blood was conducted on the following items : control test : 1 , 25 - dihydroxyvitamin d 3 [ 1 , 25 -( oh ) 2 d 3 ], calcium ( ca ), inorganic phosphorus ( ip ), and magnesium ( mg ); and 1α - vd 3 test : 1 , 25 -( oh ) 2 d 3 , ca , ip , and mg . the obtained data was analyzed by comparing the result of the biochemical examination of blood for each test cow in the 1α - vd 3 test with the result of control test and investigating the presence or absence of the intravaginal absorption of each drug . the shifts of 1 , 25 -( oh ) 2 d 3 , ca , ip , and mg concentrations in blood by the intravaginal administration of 1α - vd 3 were observed by the above - described procedure . results obtained by observing the shifts of concentrations by the intravaginal administration of 1α - vd 3 are shown in fig1 to fig4 . comparison and contemplation between the result of the present example 1 and the result of comparative example 1 below demonstrate that 1α - vd 3 is absorbed from the vaginal wall into the body by the intravaginal administration of 1α - vd 3 and quickly converted to 1 , 25 -( oh ) 2 d 3 , thereby affecting ca metabolism . no evidence that administered drugs were absorbed from the vaginal wall was confirmed in the intravaginal administration of vitamin a , vitamin d 3 , and vitamin e in comparative example 1 below . vitamin a , vitamin d 3 , and vitamin e were administered to the vaginal cavities of cows to observe biochemical changes in blood after administration in the same manner as in example 1 except that test drugs , test contents , and biochemical examination items of blood were as described in the following ( 1 ) to ( 3 ). vitamin d 3 ( vitd 3 ; bulk for drug production , liquid ); and vitad 3 e test : intravaginal administration of vita ( 10 , 000 , 000 iu )+ vitd 3 ( 5 , 000 , 000 iu )+ vite ( 920 iu ) brought up to 8 ml per cow with 20 % ethanol . control test : vita , 25 - hydroxyvitamin d 3 ( 25 - ohd 3 ), vite , calcium ( ca ), inorganic phosphorus ( ip ), and magnesium ( mg ); and the obtained data was analyzed by comparing the result of the biochemical examination of blood for each test cow in the vitad 3 e test with the result of control test and investigating the presence or absence of the intravaginal absorption of each drug . the shifts of vita , 25 - ohd 3 , and vite concentrations in blood by the intravaginal administration of vitad 3 e were observed by the above - described procedure . results obtained by observing the shifts of concentrations by the intravaginal administration of vitad 3 e are shown in fig5 to fig7 . comparison and contemplation between the result of the present comparative example 1 and the result of the above example 1 demonstrate that 1α - vd 3 in example 1 is absorbed from the vaginal wall into the body by the intravaginal administration of 1α - vd 3 and quickly converted to 1 , 25 -( oh ) 2 d 3 , thereby affecting ca metabolism , whereas no evidence that the administered drugs were absorbed from the vaginal wall was confirmed in the intravaginal administration of vitad 3 e in comparative example 1 . for confirming the absorption in the vagina of 1 , 25 -( oh ) 2 d 3 administered to the vaginal cavities of cows , biochemical changes of 1 , 25 -( oh ) 2 d 3 and minerals in blood were observed after the intravaginal administration of 1 , 25 -( oh ) 2 d 3 to cows . six holstein cows ( 3 to 6 months olds , 97 to 118 kg in body weights ) that were clinically healthy were raised and domesticated for at least 1 week in the same fence by providing them with feed ( 1 . 56 kg of grass , 0 . 55 kg of formula feed , and 1 . 44 kg of alfalfahey cube in dried forms ) having a daily mineral intake of 21 g of ca , 13 g of p , and 4 g of mg that satisfies requirements stipulated by nrc ( national research council ) on a daily basis and free water drinking . to each of five of the cows , 1 , 25 -( oh ) 2 d 3 ( crystal manufactured by mercian corporation dissolved in 99 % ethanol to bring its concentration to 1 mg / ml and cryopreserved at − 20 ° c . until just before use ) was intravaginally administered at 1 μg per kg of body weight . intravaginal administration was performed using a 14 - gauge , 64 mm - long cannula with an indwelling needle for injection ( surflo , terumo co . ltd ., tokyo ) and a plastic pump ( top plastic syringe , top surgical taiwan corporation , taiwan ). to the other cow , 3 . 0 ml of 99 % ethanol was administered as a control . a heparinized blood sample was collected from a jugular vein immediately before administration ( 0 hour ) and at 2 , 6 , 12 , 24 , 48 , 72 , and 96 hours after administration . the biochemical value of blood was indicated as a means ± standard deviation . for observing the effect of the intravaginal administration of 1 , 25 -( oh ) 2 d 3 , repeated measures analysis of variance was used . when the effect was significant , a statistical test was conducted by the dunnett &# 39 ; s multiple comparison between the value at 0 hour and each value after administration . the significant difference was set to p & lt ; 0 . 05 . although significant changes in 1 , 25 -( oh ) 2 d 3 , ca , ip , and mg concentrations in plasma were observed in the cows to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered , those varying concentrations in plasma were not affected by ethanol administration except for ip ( fig8 and fig9 ). as can be seen from fig8 , a significant change ( b ) p & lt ; 0 . 01 ) was observed in the value of the 1 , 25 -( oh ) 2 d 3 concentration in plasma of the cows to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered , as compared with the value at 0 hour . as can be seen from fig9 , significant changes ( a ) p & lt ; 0 . 05 and b ) p & lt ; 0 . 01 ) were observed in the values of the mineral ( ca , ip , and mg ) concentrations in plasma of the cows to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered , as compared with the value at 0 hour . the value of 1 , 25 -( oh ) 2 d 3 in plasma was 88 . 3 ± 20 . 3 pg / ml before administration ( 0 hour ) and significantly ( p & lt ; 0 . 01 ) increased to 1967 . 4 ± 1139 . 6 pg / ml at 6 hours after administration of 1 , 25 -( oh ) 2 d 3 , and reduced thereafter . the ca concentration in plasma of the cows to which 1 , 25 -( oh ) 2 d 3 was administered was significantly ( p & lt ; 0 . 01 ) high at 12 to 72 hours after administration as compared with the value before administration ( 10 . 4 ± 0 . 4 mg / dl ) and exhibited the maximum value ( 11 . 96 ± 0 . 7 mg / dl ) at 24 hours after administration . change in the ip concentration in plasma observed in the cow to which 1 , 25 -( oh ) 2 d 3 was administered was same as that of the cow which underwent ethanol administration . the value of ip in plasma was significantly high at 6 hours ( 8 . 1 ± 0 . 8 mg / dl ; p & lt ; 0 . 05 ) and 24 to 96 hours ( 9 . 1 ± 0 . 7 to 8 . 6 ± 0 . 6 mg / dl ; p & lt ; 0 . 01 ) after administration of 1 , 25 -( oh ) 2 d 3 as compared with the value at 0 hour ( 7 . 3 ± 0 . 5 mg / dl ). the value of mg in plasma was significantly ( p & lt ; 0 . 01 ) low at 24 and 48 hours ( 1 . 8 ± 0 . 1 and 1 . 8 ± 0 . 1 mg / dl ) after administration of 1 , 25 -( oh ) 2 d 3 as compared with the value at 0 hour ( 2 . 1 ± 0 . 1 mg / dl ). in the present result , a sudden increase and rise of 1 , 25 -( oh ) 2 d 3 in plasma were observed only in the cows at 2 hours after administration of 1 , 25 -( oh ) 2 d 3 . with that , the absorption of 1 , 25 -( oh ) 2 d 3 from the vaginal wall of a cow has been confirmed . it is noted that the state of the above - described changes in the 1 , 25 -( oh ) 2 d 3 concentration in plasma is similar to results observed in nonpregnant - nonlactating adult cows intramuscularly injected with 1 , 25 -( oh ) 2 d 3 . the main physiological effect of 1 , 25 -( oh ) 2 d 3 is to increase ca and ip concentrations in plasma by being absorbed from the intestinal tract . however , the present result from the raised cows to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered was similar to the values of ca and ip in plasma that were led to high levels by the intravenous injection of 1 , 25 -( oh ) 2 d 3 . however , in the present experimental result , an initial decrease and subsequent increase in an ip concentration in plasma were observed in the raised cow to which ethanol was administered . in similar biphasic changes in the value of ip in plasma obtained with rabbits , it is considered that hypophosphatemia was caused at an early stage by the metabolic process of ethanol catalyzed by ethanol dehydrogenase and hyperphosphatemia was subsequently induced by acetaldehyde , an ethanol metabolite thereof . therefore , the change in the ip concentration in plasma in the present experiment suggests that not only 1 , 25 -( oh ) 2 d 3 but ethanol was absorbed via the vaginal wall of a cow . the cause of hypomagnesemia after the intramuscular injection or intravaginal administration of 1 , 25 -( oh ) 2 d 3 to an adult cow is not elucidated . however , hypomagnesemia may be due to 1 , 25 -( oh ) 2 d 3 that decreases the reabsorption of mg in the renal tubule and thereby increases the renal excretion of mg . the thickness of the vaginal epithelium of a cow is considered to vary in response to the secretion of ovarian hormones . the raised cows used in the present example do not reach puberty . therefore , the absorption of 1 , 25 -( oh ) 2 d 3 from the vagina results in no change in the thickness of the vaginal epithelium . thus , the absorption is considered to be more stable in the raised cows having the thin vaginal epithelium than those in adult cows . however , the present experimental result indicates that the intravaginal administration of 1 , 25 -( oh ) 2 d 3 may be sufficient for preventing parturient hypocalcemia . the dose - response test of 1 , 25 -( oh ) 2 d 3 by an intravaginal administration route was performed with five 3 to 9 - year - old ovariectomized holstein cows having body weights of 616 to 804 kg as test animals . the cows were hitched to a partition after and provided with 5 . 3 kg of timothy hay , 0 . 18 kg of alfalfa hay , 0 . 71 kg of beet pulp pellet , and 1 . 7 kg of commercially - available grain mix on a daily basis . the cows were measured on a dm basis and freely provided with water . a daily mineral intake was set to 48 . 4 g for calcium , 20 . 2 g of inorganic phosphorus , and 12 . 7 g for magnesium , which sufficiently exceeded the nrc recommendation . to the five cows , 1 , 25 -( oh ) 2 d 3 was respectively administered at 0 . 125 , 0 . 25 , 0 . 5 , and 1 . 0 μg / kg ( by body weight ) as an intravaginal dose level and 1 . 0 μg / kg ( by body weight ) as an intravenous injection dose level at an interval of 2 weeks or more according to a 5 × 5 latin square design . the 1 , 25 -( oh ) 2 d 3 ( manufactured by mercian corporation ) used was in the form of crystalline powder , which was dissolved in 99 % ethanol at 200 μg / ml and cryopreserved at − 20 ° c . until use . a drug composed of 5 ml of 20 % ethanol solution containing 1 , 25 -( oh ) 2 d 3 at 0 . 125 , 0 . 25 , 0 . 5 , or 1 . 0 μg / kg ( by body weight ) was administered to a vaginal lumen using a split universal sheath ( imv int . co ., france ) by a rectovaginal cavity method . the vulva was then bonded with an adhesive in order to prevent the 1 , 25 -( oh ) 2 d 3 solution from being unintentionally excreted from the vaginal lumen . intravenous administration was performed using a cannula ( 14 - ga cannula for animals , manufactured by nipro medical industries ltd .) mounted in advance for the collection of a blood sample . a heparinized blood sample was collected through the cannula immediately before the administration of 1 , 25 -( oh ) 2 d 3 ( 0 hour ) and at 2 , 4 , 6 , 12 , 24 , 48 , 72 , 96 , and 120 hours after administration . next , the blood was immediately centrifuged , and 1 , 25 -( oh ) 2 d 3 , calcium , inorganic phosphorus , and magnesium concentrations in plasma were determined . urine were collected by urethral catheterization simultaneously with the collection of blood samples from the cows that underwent the intravaginal administration of 1 , 25 -( oh ) 2 d 3 at 0 . 125 and 1 . 0 μg / kg ( by body weight ) and the intravenous injection of 1 , 25 -( oh ) 2 d 3 at 1 . 0 μg / kg ( by body weight ), to determine creatinine , calcium , inorganic phosphorus , and magnesium concentrations in the urine . plasma and urine samples were cryopreserved at − 20 ° c . until analysis . as a result , there was the significant difference of changes in 1 , 25 -( oh ) 2 d 3 , calcium , inorganic phosphorus , and magnesium concentrations in plasma of the cows to which four levels of 1 , 25 -( oh ) 2 d 3 were intravaginally administered . however , a difference among groups to which different levels of 1 , 25 -( oh ) 2 d 3 were administered was not significant in plasma except for 1 , 25 -( oh ) 2 d 3 . similarly , although there was significant difference of changes in calcium , inorganic phosphorus , and magnesium in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was intravenously administered , no difference arose between groups of intravaginal administration and intravenous administration . when 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 0 . 125 , 0 . 25 , 0 . 5 , and 1 . 0 μg / kg ( by body weight ), 1 , 25 -( oh ) 2 d 3 levels in plasma significantly increased from 2 hours to 24 hours after treatment as compared with 0 hour ( 7 . 4 ± 5 . 3 , 6 . 5 ± 1 . 3 , 8 . 7 ± 5 . 6 , and 6 . 6 ± 1 . 6 pg / ml ). those levels reached peaks ( 2219 . 3 ± 812 . 0 , 3448 . 7 ± 737 . 9 , 6388 . 5 ± 1127 . 4 , and 12315 . 7 ± 2288 . 3pg / ml ) at 2 hours after administration , and reduced thereafter . there was a significant difference among groups to which 1 , 25 -( oh ) 2 d 3 were administered at 0 . 125 × 0 . 5 , 0 . 125 × 1 . 0 , 0 . 25 × 0 . 5 , 0 . 25 × 1 . 0 , and 0 . 5 × 1 . 0 μg / kg ( by body weight ) ( fig1 ). in the cow that underwent intravenous administration , 1 , 25 -( oh ) 2 d 3 in plasma became similar to those intravaginally administered by 2 hours after administration and was then changed in a similar manner . in intravaginal administration , a calcium concentration in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was administered at 0 . 125 or 0 . 25 μg / kg ( by body weight ) was significantly high from 12 hours to 120 hours after administration as compared with 0 hour ( 8 . 9 ± 0 . 5 or 8 . 9 ± 0 . 4 mg / dl ) and reached a peak ( 11 . 1 ± 0 . 9 or 11 . 2 ± 0 . 7 mg / dl ) at 48 hours after administration . alternatively , a calcium concentration in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was administered at 0 . 5 or 1 . 0 μg / kg ( by body weight ) was significantly high from 6 hours to 120 hours after administration as compared with 0 hour ( 8 . 9 ± 0 . 2 or 8 . 8 ± 0 . 7 mg / dl ) and reached a peak ( 11 . 5 ± 0 . 6 or12 . 0 ± 0 . 6 mg / dl ) at 48 hours after administration . changes in a calcium concentration ( 8 . 8 ± 0 . 5 mg / dl at 0 hour , 11 . 5 ± 1 . 2 mg / dl at a peak ) in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was intravenously administered were similar to those in the cows to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 0 . 5 or 1 . 0 μg / kg ( by body weight ) ( fig1 ). an inorganic phosphorus concentration ( 5 . 3 ± 1 . 0 , 5 . 3 ± 0 . 6 , or 5 . 4 ± 1 . 3 mg / dl at 0 hour ) in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was administered at 0 . 125 , 0 . 5 , or 1 . 0 μg / kg significantly rose at 24 hours after intravaginal administration of 1 , 25 -( oh ) 2 d 3 ( 7 . 7 ± 0 . 8 , 7 . 9 ± 0 . 9 , and 8 . 0 ± 1 . 2 mg / dl , respectively ) and reached the maximum value from 24 hours to 120 hours after administration . an inorganic phosphorus level in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 0 . 25 μg / kg was significantly high ( 6 . 7 ± 0 . 9 to 8 . 6 ± 1 . 2 mg / dl ) at 12 hours to 120 hours after administration as compared with the level at 0 hour ( 4 . 7 ± 0 . 6 mg / dl ). changes in an inorganic phosphorus concentration ( 5 . 2 ± 1 . 3 mg / dl at 0 hour ) in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was intravenously administered increased ( 7 . 2 ± 0 . 8 mg / dl ) at 12 hour after administration and reached a peak from 24 hours to 12 hours after administration ( 9 . 1 ± 1 . 6 to 9 . 0 ± 1 . 2 mg / dl ) ( fig1 ). in intravaginal administration , a magnesium concentration in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was administered at 0 . 125 , 0 . 25 , or 1 . 0 μg / kg was significantly low ( 1 . 9 ± 0 . 1 , 1 . 8 ± 0 . 1 , or 1 . 8 ± 0 . 2 to 1 . 8 ± 0 . 3 , 1 . 7 ± 0 . 2 , or 1 . 7 ± 0 . 4 mg / dl ) from 24 hours to 120 hours after administration as compared with the respective values at 0 hour ( 2 . 2 ± 0 . 2 , 2 . 0 ± 0 . 2 , and 2 . 1 ± 0 . 1 mg / dl ). a magnesium concentration in plasma of the cow to which 1 , 25 - oh ) 2 d 3 was administered at 0 . 5 μg / kg was significantly low ( 1 . 9 ± 0 . 2 to 1 . 7 ± 0 . 2 mg / dl ) from 12 hours to 120 hours after administration as compared with the value at 0 hour ( 2 . 2 ± 0 . 2 mg / dl ). changes in a magnesium concentration ( 2 . 2 ± 0 . 2 mg / dl at 0 hour , 1 . 9 ± 0 . 3 to 1 . 7 ± 0 . 2 mg / dl from 24 hours to 120 hours after administration ) in plasma of the cow to which 1 , 25 -( oh ) 2 d 3 was intravenously administered were similar to those in the cow to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 0 . 125 , 0 . 5 or 1 . 0 μg / kg by body weight ( fig1 ). significant changes were observed in the values of a calcium / creatinine ratio ( ca / cre ), an inorganic phosphorus / creatinine ratio ( ip / cre ), and a magnesium / creatinine ratio ( mg / cre ) in urine in both of the cow to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 1 . 0 μg / kg by body weight and the cow to which 1 , 25 -( oh ) 2 d 3 was intravenously administered at 1 . 0 μg / kg by body weight . there was no influence on those values in the cow to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 0 . 125 μg / kg by body weight . there was a significant difference on the value of mg / cre among groups in the cow to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 0 . 125or 1 . 0 μg / kg by body weight or the cow to which 1 , 25 -( oh ) 2 d 3 was intravenously administered at 1 . 0 μg / kg by body weight , where as no significant difference among groups arose in the values of ca / cre and ip / cre . when 1 , 25 -( oh ) 2 d 3 was administered at 1 . 0 μg / kg by body weight , the value of ca / cre in urine significantly rose via the vagina at 24 hours after administration and significantly rose via the vein at 12 hours and 24 hours after administration ( fig1 ). when 1 , 25 -( oh ) 2 d 3 was administered at 1 . 0 μg / kg by body weight , the value of ip / cre in urine significantly was significantly high via the vagina from 48 hours 120 hours after administration and via the vein from 72 hours to 120 hours after administration , as compared with the values immediately before administration ( fig1 ). when 1 , 25 -( oh ) 2 d 3 was administered at 1 . 0 μg / kg by body weight , the value of mg / cre in urine was significantly high via the vagina from 6 hours to 12 hours after administration and via the vein at 6 hours after administration ( fig1 ). individual bioavailability of the five cows was 71 . 1 , 124 . 2 , 113 . 3 , 90 . 0 , and 66 . 5 %, respectively . it is noted that the bioavailability was determined by comparing an area under the plasma concentration - time curve ( auc ) between the cow to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 1 . 0 μg / kg ( by body weight ) and the cow to which the same amount of 1 , 25 -( oh ) 2 d 3 was intravenously administered , and a auc ratio between intravaginal administration and intravenous administration was indicated by percentage . the present result indicates that 1 , 25 -( oh ) 2 d 3 administered into the vaginal lumen of the ovariectomized cow is absorbed from the vaginal wall proportionately with a dose for all of the four different doses . in addition , the amount of 1 , 25 -( oh ) 2 d 3 administered into the vaginal lumen has no dose - relationship with changes in calcium , inorganic phosphorus , and magnesium concentrations in plasma after administration . in spite of increases in calcium and inorganic phosphorus concentrations in plasma and a decrease in a magnesium concentration in plasma , the excretion of minerals to urine was not affected when 1 , 25 -( oh ) 2 d 3 was administered at 0 . 125 μg / kg by body weight . in this case , approximately 93 % of 1 , 25 -( oh ) 2 d 3 administered to the vaginal lumen was considered to enter into the circulatory system throughout the body . although it is known that a proportional rise in the auc ( area under the plasma concentration - time curve ) of calcitriol in serum with an increase in a dose was not observed in oral administration ( report by muindietal ., ( 2002 ); pharmacokinetics of high - dose oral calcitriol : results from a phase i trial of calcitriol andpaclitaxel . clin . pharmacol . ther . 72 : 648 - 659 ), the present result indicates that 1 , 25 -( oh ) 2 d 3 is dose - dependently absorbed from the vaginal wall , so that the superiority of the vaginal administration of 1 , 25 -( oh ) 2 d 3 is clear in this regard . it is also known that the excretion of calcium into urine increases in cows to which 1 , 25 -( oh ) 2 d 3 is intravenously administered at four dose levels ( 30 , 90 , 270 , and 600 μg ) and this increase is not directly related to the dose of steroid in the vein ( report by hoffsis et al ., ( 1979 ); the use of 1 , 25 - dihydroxycholecalciferol in the prevention of parturient hypocalcemia in dairy cows ., bovine practitioner 13 : 88 - 95 ). however , in the present result , the amount of calcium excreted into urine had no significant increase in the cow to which 1 , 25 -( oh ) 2 d 3 was intravaginally administered at 0 . 125 μg / kg by body weight , in spite of the increase in a calcium concentration in plasma . results from changes in the excretion of inorganic phosphorus and magnesium into urine were similar to that of the excretion of calcium into urine . those results indicate that , of four doses for the administration of 1 , 25 -( oh ) 2 d 3 to the vaginal lumen , a dose of 0 . 125 μg / kg by body weight is appropriate . however , in the lowest dose level ( 0 . 125 μg / kg by body weight ), calcium and inorganic phosphorus concentrations in plasma also increased and magnesium in plasma decreased in a similar manner as the other dose levels . the bioavailability of 1 , 25 -( oh ) 2 d 3 via the vagina has not been known so far . the bioavailability of 1 , 25 -( oh ) 2 d 3 at 24 hours after administration of calcitriol at a dose of 60 ng / kg to a young patient dialyzed for a long period is known to be 62 % via the mouth and 67 % via the peritoneal cavity ( report by salusky et al ., ( 1990 ); pharmacokinetics of calcitriol in continuous ambulatory and cycling peritoneal dialysis patients . am . j . kidney dis . 16 : 126 - 32 ). this report suggests that a first - pass effect in an intestine and / or a liver and a dialysate system of the peritoneal cavity decrease the bioavailability . the bioavailability shown in the present result ( approximately 93 %) is obviously higher than that in the report . accordingly , the present result indicates that an effective route via which 1 , 25 -( oh ) 2 d 3 is administered to a dairy cow is the vaginal cavity . the present result indicates that 1 , 25 -( oh ) 2 d 3 administered to the vaginal lumen is dose - dependently absorbed to a cow , and also indicates that a suitable dose for the administration of 1 , 25 -( oh ) 2 d 3 to the vaginal lumen is the lowest dose ( 0 . 125 μg / kg by body weight ) although the administration of 1 , 25 -( oh ) 2 d 3 to a cow at a lower dose may affect blood and urine components . according to a method of transvaginally administering a vitamin d derivative to a domestic mammal of the present invention , the prevention , cure , and / or treatment of diseases such as astasia caused by hypocalcemia of a domestic mammal , especially a cow are readily performed for the following reasons : ( 1 ) the vitamin d derivative is readily administered without medical equipment ; ( 2 ) the substance is efficiently absorbed from the vagina without undergoing first - pass metabolism in the liver ; ( 3 ) its delivery type in administration can have a wide choice of options for a form including a gel , a tablet , a microsphere , and cidr ( controlled internal drug release : a kind of tampon system ); and ( 4 ) the vitamin d derivative is quickly absorbed because of the use of the vagina composed of tissue in which blood supply is well developed .
the present invention provides a method of preventing , curing , and / or treating hypocalcemia of a domestic mammal , especially , a cow . specifically , the present invention provides a method of administrating a vitamin d derivative to prevent , cure and / or treat hypocalcemia , characterized in that a vitamin d derivative , especially , 1α - hydroxyvitamin d 3 and / or 1 . 25 - dihydroxyvitamin d 3 is transvaginally administered to a domestic mammal .