Incorporation of Cestrum diurnum leaf improves intestinal Ca transport in broilers.

The economy of Ca utilization is under the control of vitamin D(3), particularly its active metabolite 1,25-dihydroxy cholecalciferol [1,25(OH)(2)D(3)]. In sufficient Ca absorption leads to tibial dyschondroplasia resulting in not attaining optimum body weight. Our earlier studies [T.P. Prema, N. Raghuramulu, Phytochemistry 37 (1994) 167] have shown that the Cestrum diurnum (CD) leaves contain vitamin D(3) metabolites. It was felt whether incorporation of CD as a source of 1,25(OH)(2)D(3) could improve the Ca absorption in broilers. Four groups of 60 birds each were fed with either normal diet or normal diet+0.25% CD or normal diet without vitamin D(3) or normal diet without vitamin D(3)+0.25% CD leaf powder for 45 days. In subsample of six birds it was observed that incorporation of CD leaves in the feed had the maximal effect on all the parameters studied. The results indicate that the intestinal Ca transport as represented by Serosa/Mucosa (S/M) ratio was found to be significantly (p<0.01) higher in broilers fed diet with CD leaf powder and the 1alpha hydroxylase activity in kidney is significantly (p<0.001) higher in negative controls. On the other hand the supplementation of CD leaves enhanced the serum Ca, body weight, tibia weight, density and strength resulting in the disappearance of tibial dyschondroplasia. No lesions of toxicity were observed in any of the soft tissue examined. The results suggest that the incorporation of CD leaf powder in poultry feed could be beneficial to the poultry.

Cestrum diurnum leaf as a source of 1,25(OH)2 Vitamin D3 improves egg shell thickness.

A continuing concern of the poultry industry is the high incidence (12%) of egg losses in the laying house due to poor egg shell quality. Calcium (Ca) homeostasis is a key factor in egg shell formation. The economy of Ca utilisation is under the control of Vitamin D(3), particularly its active metabolite 1,25-dihydroxy cholecalciferol [1,25(OH)(2)D(3)]. Supplementation of 1,25(OH)(2)D(3) has been shown to increase specific gravity, shell thickness and shell weight of the egg. However, commercially available synthetic 1,25(OH)(2)D(3) is very expensive. Earlier studies from our Institute [Phytochemistry 37 (1994) 677] have identified a cheap, natural and rich source of 1,25(OH)(2)D(3) in the leaves of Cestrum diurnum (CD), a member of the Solanaceae family. In this study, CD leaves were explored as a source of 1,25(OH)(2)D(3) in the feed of layer birds to improve the egg shell thickness. Fifteen-week-old white leghorn layers were divided into four treatments of 60 birds each and as follows: (I) normal diet with Vitamin D(3), (II) normal diet with Vitamin D(3) + CD, (III) normal diet without Vitamin D(3) and, (IV) normal diet without Vitamin D(3) + CD powder. CD leaf powder was incorporated in to the feed at 0.3% level. The experimental feeding was continued up to 72 weeks of age of the birds. Weekly food intake and daily egg production were noted throughout the experimental period and the specific gravity of the eggs, feed consumed to lay one egg and egg shell thickness were determined. Incorporation of CD leaves in the feed had the maximal effect on all the parameters studied. The feed consumed to lay one egg was 20 g less than the control group. The specific gravity of the egg was higher by 0.005, than the control egg, indicating a 5% decrease in the breakage of eggs in CD fed chicks. Also there was a significant increase (P < 0.001) in egg shell thickness. The data suggest that incorporation of CD leaf powder in the feed of poultry layers increased the egg shell thickness, which in turn could decrease the economic loss due to breakage of eggs.

Vitamin D deficiency reduces insulin secretion and turnover in rats.

Vitamin D deficiency can result in low serum insulin levels, which lead to impaired glucose tolerance. The present study was conducted to assess the mechanisms of this impairment. Pancreatic secretion of insulin and insulin turnover in vitamin D-deficient rats were studied. Insulin secretion was found to be significantly decreased in vitamin D-deficient rats compared to control rats. Supplementation with calcium alone could reverse the defect. The impaired insulin secretion observed in vitamin D deficiency was not specific to glucose stimulation but was also seen in response to arginine. Insulin turnover was studied in vivo using A14-(125)I-insulin. The pharmacokinetic parameters (elimination rate constant K, insulin biological half-life, t1/2, plasma concentrations of insulin at time zero I0) were calculated from the plasma radioactivity. The vitamin D-deficient rats had a lower degradation rate than controls. These findings suggest that vitamin D deficiency leads to reduction in both insulin secretion and turnover, and that the reduced turnover could be an adaptive mechanism to conserve the low amounts of insulin secreted.

Oral glucose tolerance is unaltered in vitamin D-deficient rat.

Vitamin D deficiency has been reported to result in impaired glucose tolerance and decreased insulin secretion when glucose is administered either intravenously or intraperitoneally. The aim of the present study was to study oral glucose tolerance and glucose absorption in a vitamin D-deficient rat model. Oral glucose tolerance tests were carried out in vitamin D-deficient and control rats, and this was found to be unaltered in the deficient state. Intestinal absorption of glucose was drastically reduced in the deficient animal and was found to be due to a reduction in the sodium-dependent component of glucose transport. Thus the unaltered oral glucose tolerance in the vitamin D-deficient rat is probably due to impaired absorption of glucose.

Vitamin D3 and its metabolites have no role in calcium and phosphorus metabolism in Tilapia mossambica.

The physiological function of vitamin D in fishes still remains uncertain. Earlier we observed no relationship between vitamin D3 content of several freshwater fishes and their calcemic/phosphatemic status and bone mineral content. In the present study the effects of vitamin D3 and its metabolites, 25-hydroxy vitamin D3 (25-OH-D3) and 1,25-dihydroxy vitamin D3 [1,25-(OH)2D3], administration on serum calcium-phosphorus levels, intestinal calcium absorption, whole-body calcium-phosphorus uptake, and gill calcium binding protein (CaBP) activity in the freshwater fish, Tilapia mossambica (Tilapia) was examined. It was observed that vitamin D3 and its metabolites could alter neither serum calcium-phosphorus levels nor intestinal calcium absorption and gill CaBP activity in fish at various doses. Further, the whole-body uptake of labelled calcium and phosphorus was also unaffected by vitamin D3/1,25-(OH)2D3 at different levels and/or at various lengths of time. Thus these studies indicate that unlike in terrestrial vertebrates, vitamin D3 or its metabolites are not needed for calcium-phosphorus homeostasis in fish.

Vitamin D2 is not biologically active for Rora (Labeo rohita) as vitamin D3.

The present investigation was directed towards finding the relative biopotency of vitamin D3 and D2 in fish. The freshwater column feeder fish Labeo rohita (Rora) was used for the study. The feeding of Rora with graded levels of vitamin D2 (550, 1,100 and 1,650 i.u./kg diet) and vitamin D3 (1,100 and 1,650 i.u./kg diet) resulted in no behavioural or morphological changes in comparison with the group fed a vitamin D-deficient diet. Also, the growth rate, feed efficiency, mortality rate, carcass protein, total lipids, calcium and phosphorus were found to remain unaltered in the vitamin D-deficient fish and fish fed any form of the vitamin. Further, there is no difference in any of the above parameters between the different doses of vitamin D3 or vitamin D2. Thus, the results of this study indicate that both of the forms of vitamin D (D2 or D3) are not biologically active for Rora (Labeo rohita) as a representative of freshwater fish.

Vitamin D is not an essential nutrient for Rora (Labeo rohita) as a representative of freshwater fish.

This investigation was directed towards finding the need of vitamin D for fish. The freshwater column feeder fish Labeo rohita (Rora) was used for the study. Early fry stage fish were divided into four experimental groups of 350 each: two groups were kept in natural light, while the other two were maintained under total darkness. One each of the light and dark-grown groups was supplied dietary vitamin D3 [1,650 i.u/kg diet], whereas the other groups were fed a vitamin D-deficient diet for six months. The known vitamin D-related functions and growth parameters were studied in these four experimental groups of fish. The results showed that fish reared on vitamin D-deficient diet and in dark did not have even traces of liver vitamin D, indicating a state of vitamin D deficiency in these fish. No significant differences were observed in percent bone to body weight or dry matter of the vitamin D-deficient/supplemented groups of fish grown in light/dark. Further, it was also observed that there were no significant changes in bone and carcass ash or calcium and phosphorus content in response to vitamin D3 supplementation as compared to the groups which did not receive vitamin D3 (grown both in light and dark). Also, there was little change in several other parameters like carcass protein and lipid, mortality rates, hepatosomatic index, and feed efficiency between the vitamin D-deficient/supplemented groups of fish. Thus, these findings suggest that vitamin D may not be an essential nutrient for Rora (Labeo rohita) as a representative of freshwater fish.

Vitamin D3 and its metabolites in the tomato plant.

The tomato plant has been demonstrated to have vitamin D-like activity. The activity was present in the leaves but not in the fruit of the plant. The chloroform extract of the leaves (containing free vitamin D and its metabolites) and the ethanol extract of the residue (containing the glycosidic forms) were partially purified by column chromatography. The fractions corresponding to authentic vitamin D3, 25-hydroxy vitamin D3 and 1,25-dihydroxy vitamin D3 were tested for biological activity and analysed by HPLC. The results indicate that the plant contains vitamin D3, 25-hydroxy vitamin D3 and 1,25-dihydroxy vitamin D3 and their glycosidic forms. Free vitamin D3 was observed to be the major active principle and the concentration of the free forms of the metabolites was higher than the corresponding glycosides.

Studies on vitamin D metabolism in malnourished children.

1. Basal levels of serum 25-hydroxy vitamin D (25-OHD) were estimated in ten normal children and twenty-seven children with protein-energy malnutrition. 2. Five normal children and fourteen malnourished children were administered a single massive dose of 15 mg vitamin D orally and the remaining children received oral supplements of 50 micrograms vitamin D daily for 20 d. Blood samples were obtained after 10 and 20 d of dosing and serum 25-OHD levels were repeated. 3. The basal serum 25-OHD levels were significantly lower (P less than 0.05) in malnourished children than in normal children. 4. Administration of a single massive dose of vitamin D as well as daily supplementation of small doses resulted in significant increases in serum 25-OHD levels within 10 d. However, the increase with a massive dose was of a higher magnitude. There was no significant difference between the normal and malnourished children. 5. The binding capacity of serum to 25-OHD was similar in both the groups. 6. These results suggest that vitamin D metabolism is not altered in protein-energy malnutrition.

Serum 25-hydroxy-vitamin D levels in malnourished children with rickets.

Serum levels of calcium, phosphorus, alkaline phosphatase, and 25 hydroxy-vitamin D (25-OH-D3) were measured in normal and malnourished children with and without rickets. Children with rickets had clinical, biochemical, and x-ray evidence of the disease; most of them were malnourished. 25-OH-D3 levels were lower than in normal children. After treatment with vitamin D their condition improved. 25-OH-D3 levels were also found to be reduced in malnourished children without rickets. These studies show that rickets is common in malnourished children. Inadequate exposure to sunlight appears to be the factor mainly responsible for the high incidence of the disease. In addition, malnutrition perhaps contributes to the development of rickets.

Antimicrobial factors in human milk.

Levels of immunoglobulins, lactoferrin and lysozyme were determined in milk samples obtained from well-nourished and under-nourished Indian women at different stages of lactation. The concentration of immunoglobulins and lactoferrin was higher in colostrum than in mature milk while the lysozyme levels showed a progressive increase with the period of lactation. There were no significant differences in the levels between the two groups of women. Administration of iron did not alter either the total or percentage saturation of lactoferrin in milk. These results indicate that antibacterial factors in milk are not influenced by the nutritional status of the mother and that iron supplementation does not interfere with the bacteriostatic function of lactoferrin.

PIP: Lower incidences of infection among breastfed vs. bottlefed infants have been attributed, not only to bottle contamination, but to the presence of various antibacterial factors in breast milk. 3 of these factors, immunoglobulins, lysozyme, and lactoferrin, were quantitated from milk samples from well-nourished and under-nourished Indian women in various stages of lactation. An ancillary concern of this study was to determine whether iron supplementation in under-nourished lactating women might abolish the bacteriostatic mechanism of lactoferrin by altering its saturation in milk, thus interfering with its biological function. 250 women gave breast milk samples for study. In addition, 11 lactating women were given 200 mg of iron intramuscularly, and their milk samples were assayed. In the nonsupplemented women, the concentration of immunoglobulin A (IgA) was high in colostrum, with a mean level of 350 mg/100 ml, and fell rapidly during the first 4 weeks of lactation, to a mean level of 110 mg/100 ml. IgG concentration was slightly higher in colostrum than in mature milk. Lactoferrin concentration was very high in colostrum, with a mean level of 600 mg/100 ml, and fell progressively up to 5 months of lactation, stabilizing at a mean level of 180 mg/100 ml. Lysozyme content of colostrum was lower than that of mature milk and showed a progressive increase with duration of lactation; its highest level of 42 mg/100 ml was reached at 12 months. No significant differences in levels of immunoglobulins, lactoferrin, and lysozyme were found between well-nourished and under-nourished mothers. In women who received the iron supplements, at first the mean level of total lactoferrin was 240 mg/100 ml, 9% of which was saturated. No significant changes in concentrations of either total or saturated lactoferrin were found after administering the iron supplement.