Levels Of Dietary Potassium Research Articles

Potassium-Induced Changes in Muscle Free Amino Acid Concentrations in Chicks

Two experiments with purified crystalline amino acid diets were conducted to determine the effect of dietary potassium level on chick breast muscle free amino acid concentrations. In both experiments, concentrations of muscle free glutamine, lysine and arginine increased as dietary potassium increased from 0.12 to 0.18% and decreased as dietary potassium exceeded 0.18%. As dietary potassium increased, muscle potassium concentration increased linearly with an equivalent linear decrease in muscle sodium concentration. Peak concentrations of muscle free glutamine, lysine and arginine occurred in muscle with a K+:Na+ ratio of approximately 1.4. Concentrations of the three amino acids were less in muscle with K+:Na+ ratios either less than or greater than 1.4. Breast muscle concentrations of free histidine decreased slightly, while muscle free carnosine increased substantially when dietary potassium exceeded 0.18%.amino acids glutamine lysine arginine potassium

Interaction between dietary potassium intake and TNF-α rs1800629 genetic polymorphism in gastric cancer risk: a case-control study conducted in Korea.

Mineral consumption has been suggested to have an impact on gastric cancer (GC) prevention. However, the protective effect of potassium against gastric carcinogenesis remains inconclusive. The causal link between inflammation and cancer is well established. Notably, potassium intake and potassium channels may play certain roles in regulating the production of TNF-α (TNF-α). We aimed to determine whether dietary potassium intake is related to the risk of GC. We further observed whether this association was modified by TNF-α rs1800629. We designed a case-control study comprising 377 GC cases and 756 controls. Information on dietary potassium intake was collected using a semiquantitative food frequency questionnaire. Genotyping was performed by the Affymetrix Axiom Exom 319 Array platform. Unconditional logistic regression models were used to assess associations. A significantly reduced GC risk was found for those who consumed higher dietary potassium levels (OR = 0·63, 95 % CI = 0·45, 0·89, P for trend = 0·009). In the dominant model, we observed a non-significant association between TNF-α rs1800629 and GC risk (OR = 1·01, 95 % CI = 0·68, 1·49). In females, those who were homozygous for the major allele (G) of rs1800629 with a higher intake of dietary potassium exhibited a decreased risk of GC (OR = 0·40, 95 % CI = 0·20, 0·78, P interaction = 0·041). This finding emphasises the beneficial effect of potassium intake on GC prevention. However, this association could be modified by TNF-α rs1800629 genotypes. A greater protective effect was exhibited for females with GG homozygotes and high potassium intake.

Lower dietary mineral intake is significantly associated with cervical cancer risk in a population-based cross-sectional study.

Population-based studies investigating the association between dietary mineral intake and risk of cervical intraepithelial neoplasia (CIN) or cervical cancer in Chinese women are few. We performed a cross-sectional analysis of screening data obtained from 2,304 women in 2014 within an ongoing cohort study comprising 40,000 women in China. Dietary intake was assessed using a semiquantitative food frequency questionnaire. Nutrition intake was calculated using a 26-item list of food sources drawn from a validated, comprehensive database. All participants were surveyed through in-person interviews, physical examinations, and laboratory tests. The Pearson chi-square test was used for categorical variables. Multivariable logistic regression models were used to evaluate the relationship between dietary mineral intake and CIN+ risk. The food frequency questionnaire exhibited acceptable reproducibility and reasonable validity in assessing nutrient intakes among these women. After adjusting for multiple potential confounders, low dietary calcium intake was associated with CIN2+ risk (first versus fourth quartile: odds ratio [OR]=1.52, 95% confidence interval [CI]: 1.01-2.32). Similar for magnesium (OR=1.80, 95% CI: 1.20-2.68), phosphorus (OR=1.69, 95% CI: 1.12-2.55), zinc (OR=1.55, 95% CI: 1.03-2.34), and potassium (OR=1.92, 95% CI: 1.28-2.88). Low dietary intakes of calcium and potassium were significantly associated with CIN1 risk. Increased CIN2+ risk correlated with rates of no oral contraceptives and lower levels of dietary Potassium. These results thus proposed that low dietary mineral intake was an independent risk factor, potential synergy may exist between low dietary mineral levels and oral contraceptives contribute to the development of higher-grade CIN and cervical cancer.

The association of potassium intake with bone mineral density and the prevalence of osteoporosis among older Korean adults.

BACKGROUND/OBJECTIVESOsteoporosis is characterized by low bone mass and results in vulnerability to fracture. Calcium and vitamin D are known to play an important role in bone health. Recently, potassium has been identified as another important factor in skeletal health. We examined the link between potassium intake and bone health among the Korean older adult population.SUBJECTS/METHODSThis retrospective, cross-sectional study included 8,732 men and postmenopausal women over 50 years old who completed the Korean National Health and Nutrition Survey (KNHANES) between 2008 and 2011. Potassium consumption was evaluated using a 24-hour recall method. Bone mineral density (BMD) was measured at three sites (total hip, femur neck, and lumbar spine) by dual-energy X-ray absorptiometry (DEXA). Multinomial logistic regression was used to examine the link between potassium intake and prevalence of osteoporosis and osteopenia, after controlling for potential confounding variables.RESULTSThe BMD of the total femur and Ward's triangle were significantly different according to the potassium intake among men (P = 0.031 and P = 0.010, respectively). Women in the top tertile for potassium intake showed higher BMD than those in the bottom tertile at all measurement sites (all P < 0.05). Daily potassium intake was significantly related to a decreased risk of osteoporosis at the lumbar spine in postmenopausal women (odds ratios: 0.68, 95% confidence interval: 0.48-0.96, P trend = 0.031). However, the dietary potassium level was not related to the risk of osteoporosis in men.CONCLUSIONCurrent findings indicate that higher dietary potassium levels have a favorable effect on bone health and preventing osteoporosis in older Korean women.

Effect of threonine and potassium carbonate supplementation on performance, immune response and bone parameters of broiler chickens

ABSTRACTThis study aimed to investigate the effect of different levels of dietary threonine (i.e. 100%, 110% and 120% of Ross recommendations) and potassium (i.e. 0.85% and 0.94% of diet) on performance, immune response, and bone parameters broiler chickens. Three hundred one-day-old male broiler chickens (Ross 308) were randomly assigned to 1 of 6 dietary treatments in a completely randomized design with a 3 × 2 factorial arrangement. Growth performance was not affected by dietary treatments. Birds fed diet containing 120% threonine and high potassium level were exhibited a lower immune response to phytohemagglutinin-P (PHA-P) as compared to control group (P < .05). Addition of 120% threonine with 0.94% potassium decreased heterophil percentage and heterophil to lymphocyte ratio and increased lymphocyte percentage (P < .05). Tibia and femur width and ash, Ca and P percentage of tibia, and breaking strength of bones were not influenced by dietary potassium level, whereas the width of tibia and femur was increased in broiler chickens received diet containing 120% threonine and 0.94% potassium compared to control group (P < .05). It is concluded that broiler chickens FI during starter period, cell mediated immune response and blood hematology were influence by dietary threonine and potassium interaction.

Quantifying the dietary potassium requirement of subadult grass carp (Ctenopharyngodon idellus)

A growth trial lasting for 12 weeks was conducted in a semi flow-through system to determine the dietary potassium requirement of juvenile grass carp (Ctenopharyngodon idellus) with an initial body weight of 4.8 g. Seven isonitrogenous and isoenergetic semi-purified diets were compounded with different dietary potassium levels: 1.50, 2.32, 3.28, 5.30, 7.12, 9.45 and 10.44 g kg(-1) diet. The results showed that specific growth rate and feed efficiency of grass carp were significantly (P 0.05). The Na+-K+ ATPase activity value in the gills varied significantly (P 0.05). Body potassium and moisture contents increased and lipid content decreased with dietary potassium content, while ash content in fish body increased first and then decreased as potassium content increased (P < 0.05). Body protein in the 10.44 g kg(-1) group was significantly lowered (P < 0.05). However, calcium, magnesium, phosphorus and sodium contents in dry matter were not affected by dietary potassium level. When the potassium content of water was 1.86-3.10 mg L-1, judging from the polynomial regression analysis for the specific growth rate of fish and the Na+-K+ ATPase activity in the gill, and the broken-line analysis for body potassium content, the optimal dietary potassium content for juvenile grass carp was 4.65, 7.27 and 5.98 g kg(-1) diet respectively. (C) 2014 Elsevier B.V. All rights reserved.

Quantifying the dietary potassium requirement of juvenile grass carp (Ctenopharyngodon idellus)

A growth trial lasting for 12 weeks was conducted in a semi flow-through system to determine the dietary potassium requirement of juvenile grass carp (Ctenopharyngodon idellus) with an initial body weight of 4.8 g. Seven isonitrogenous and isoenergetic semi-purified diets were compounded with different dietary potassium levels: 1.50, 2.32, 3.28, 5.30, 7.12, 9.45 and 10.44 g kg(-1) diet. The results showed that specific growth rate and feed efficiency of grass carp were significantly (P 0.05). The Na+-K+ ATPase activity value in the gills varied significantly (P 0.05). Body potassium and moisture contents increased and lipid content decreased with dietary potassium content, while ash content in fish body increased first and then decreased as potassium content increased (P < 0.05). Body protein in the 10.44 g kg(-1) group was significantly lowered (P < 0.05). However, calcium, magnesium, phosphorus and sodium contents in dry matter were not affected by dietary potassium level. When the potassium content of water was 1.86-3.10 mg L-1, judging from the polynomial regression analysis for the specific growth rate of fish and the Na+-K+ ATPase activity in the gill, and the broken-line analysis for body potassium content, the optimal dietary potassium content for juvenile grass carp was 4.65, 7.27 and 5.98 g kg(-1) diet respectively. (C) 2014 Elsevier B.V. All rights reserved.

The effect of different dietary potassium and chloride levels on performance and excreta dry matter in broiler chickens

The aim of this 3 &amp;times; 3 factorial experiment on broilers was to investigate the effect of different dietary levels of potassium and chloride on chicken performance, carcass composition and dry matter content in excreta. 360 one-day-old Ross 308 chickens were allocated to 9 groups, in 5 replications of 8 birds (4 ♂ and 4 ♀). Chickens from 1 to 42 days of age were kept in cages with wire floors to enable excreta collection, and were administered water and feed ad libitum. The basal starter (days 1&amp;ndash;14) and grower (days 15&amp;ndash;42) diet contained in 1 kg, as analysed, 2.11 g and 2.10 g chloride, 8.6 g and 7.8 g potassium and 2.04 g and 1.93 g sodium, respectively. Basal diets were supplemented with potassium and chloride containing, as analysed, 11.1 g or 10.6 g and 11.8 g or 11.9 g K and 2.95 g or 2.58 g and 3.16 g or 2.70 g/kg Cl, for the starter or grower periods of feeding, respectively. The sum of cations (K + Na) in diets used in the experiment ranged from 309 mEq to 390 mEq in the starter diet and from 283 mEq to 388 mEq/kg in the grower diet; the dietary electrolyte balance (DEB) values varied from 219 mEq to 331 mEq and from 207 mEq to 329 mEq/kg, respectively. During the starter feeding period the body weight gain (BWG) and feed conversion (FCR) were positively affected by increasing the chloride supplement and decrease of DEB values from 298 to 274 mEq/kg (P &amp;le; 0.001). In the grower period and throughout the feeding period, the positive effect of chloride supplementation on BWG and FCR was not confirmed but a negative effect of potassium was found out. The interaction between dietary levels of chloride and potassium found for BWG and FCR suggests a reciprocal relationship for both electrolytes. Dry matter in excreta was decreased when the K level in the diet was increased to 11.9 g/kg and DEB value to 319 mEq/kg (P &amp;le; 0.001) but breast meat yield (P &amp;le; 0.01) and relative mass of heart in carcass (P &amp;le; 0.05) were increased. Dietary chloride content elevated from 2.2 to 2.58 g/kg reduced pH in breast meat after 24 h (P &amp;le; 0.001), whereas elevated potassium content (7.8 vs. 10.6 g/kg) reduced drip loss in 24 (P &amp;le; 0.01) and 48 h stored meat (P &amp;le; 0.05).

The effect of dietary potassium and sodium on performance, carcass traits, and nitrogen balance and excreta moisture in broiler chicken

The aim of the 3 × 3 factorial experiment on broilers was to investigate the effect of high dietary levels of potassium (K) and different levels of sodium (Na) on chicken performance, carcass traits, dry matter content in excreta and nitrogen balance. Three hundred and sixty one-day-old Ross 308 chickens were allocated to 9 groups, in 5 replicates of 8 (4♂ and 4♀). Chickens from 1 to 42 days old were kept in cages with wire floors to enable excreta collection, and were provided with water and feed ad libitum. The basal starter (days 1-14) and grower (days15-42) diets contained, as analysed, 1.73 g and 1.89 g·kg -1 chloride (Cl), 10.7 g and 10.8 g K and 0.69 and 0.94 g Na, respectively. Basal diets were supplemented with cations containing, as analysed, 12.2/11.8 g and 12.7/12.5 g·kg -1 K and 1.22/1.25 g and 1.68/1.61 g·kg -1 Na, for the starter/grower periods of feeding, respectively. The molar proportion of Na:K in diets used in the experiment ranged from 0.09 to 0.27 in the starter diet and from 0.13 to 0.25 in the grower/finisher diet; the dietary electrolyte balance (DEB) values varied between 255 to 349 and 264 to 336, respectively. During the starter feeding period, body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) in the chickens were positively affected by increasing the Na supplement. Throughout the feeding period, Na supplementation improved BWG, FI and FCR and production index values and increased carcass yield. The dry matter content of the excreta was negatively affected by the K level in the diet; the 12.7 g K dietary content, in particular, caused a higher moisture content.

Effects of seawater potassium concentration on the dietary potassium requirement of Litopenaeus vannamei

Effects of seawater potassium concentration on the dietary potassium requirement of Litopenaeus vannamei were studied under the condition of artificial seawater at salinity 30‰. Three potassium concentrations in the water were set: 332, 156 and 104 mg l − 1 . And the potassium contents of the casein-gelatin-based experimental diets were 1.09%, 1.53%, 2.49% and 3.46%, respectively. The feeding trial lasted for 56 days. Growth, feeding, nutrient retention and feed conversion efficiency of the shrimp were significantly affected by the potassium concentration in the seawater ( P < 0.05), but the dietary potassium levels showed little effect .The final body weight, specific growth rate, protein efficiency ratio and feed conversion efficiency of shrimp exposed to 104 mg l − 1 water potassium level were, respectively, more than 37%, 26%, 25% and 27.5% lower than of those exposed to higher water potassium levels ( P < 0.05). No significant interaction effects were found between seawater potassium concentration and dietary potassium level. Neither seawater potassium concentrations nor dietary potassium levels influenced the body potassium content. It indicated that L. vannamei may have poor ability of assimilating potassium from dietary sources efficiently at salinity 30‰, and dietary supplementation of potassium had limited effect on improving growth of the shrimp while environmental potassium was sufficient.

Dietary levels of potassium for broiler chickens

Three experiments were conducted to determine the nutritional requirements of potassium (K) for male Ross broiler chickens, from 8 to 21, 22 to 42 and 43 to 53 days of age. The following parameters were evaluated: body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR). In each experiment, a completely randomized experimental design was used, with six treatments (K levels), and six, eight and eight numbers of replicates, and eight, five and four birds per pen, respectively. The experimental diets were basal diets deficient in K but supplemented with K carbonate to result in levels of 0.30, 0.44, 0.58, 0.72, 0.86 and 1.00% K. Estimated requirements for BWG were 0.628, 0.714 and 0.798% K, for the periods 8-21, 22-42 and 43-53 d, respectively.

Potassium intake is related to nocturnal blood pressure dipping

Sodium restriction and high levels of dietary potassium may contribute to a greater nocturnal decline in blood pressure. To evaluate the association of nutrient intake with the nighttime blood pressure dip, we measured 24-hour sodium and potassium excretion and performed ambulatory blood pressure monitoring in a sample of 165 young men and women with normal or mildly elevated blood pressure. Participants included 85 African-Americans and 80 whites with an average age of 33±6 years. Daytime systolic blood pressure averaged 125±13 mmHg, with a mean nighttime dip of 16±7 mmHg. The 24-hour sodium excretion averaged 137±61 mEq/24 hr, and potassium excretion averaged 52±25 mEq/24 hr. African-Americans and whites had similar levels of sodium excretion (132±64 vs 144±58 mEq/24 hr, p=NS), but potassium excretion was significantly lower in African-Americans (38±24 vs 59±28 mEq/24 hr, p<0.001). The nocturnal dip in systolic blood pressure was correlated with potassium excretion (r=0.25, p<0.01), and this association remained significant after adjusting for race (p<0.05) and for daytime blood pressure (p<0.01). Subjects with low potassium excretion (≤50mEq/24 hr) and those with high potassium excretion (>50mEq/24 hr) were similar in age (34±6 vs 33±6 years, p=NS) and daytime systolic blood pressure (124±13 vs 127±12 mmHg, P=NS), but participants with low potassium excretion were more often African-American (72% vs 22%, p<0.01) and had a smaller nighttime systolic blood pressure dip (15±7 vs 18±7 mmHg, p<0.01). In contrast, low sodium intake was not associated with a greater nocturnal systolic blood pressure decline. These results suggest that potassium consumption may be an important determinant of the nocturnal fall in blood pressure, and that dietary factors may contribute to ethnic differences in diurnal blood pressure variation.

Potassium requirement of fingerling channel catfish, Ictalurus puntatus

An 8-week feeding study was conducted to determine the potassium requirement of juvenile channel catfish. Six dietary levels of potassium ranging from 0.01 to 0.49% were fed to triplicate groups of catfish (initial average weight of 16.6 g) in flow-through aquaria at a water temperature of 26.7 ± 1.1 °C. The rearing water contained 4 mg/l potassium. No significant differences were observed in either weight gain or feed efficiency among the experimental groups. No dose-response relationship was apparent between dietary potassium level and whole body potassium concentration, indicating that these animals do not have a dietary requirement for potassium with potassium in the rearing water at a concentration of 4 mg/l or higher. However, when these data were used to calculate the whole body potassium balance for each group of fish it became clear that the fish do have a potassium requirement that can be met by either dietary potassium or the uptake of potassium from the rearing water. Linear regression analysis of the dietary potassium levels vs. whole body potassium balance values indicated a potassium requirement value of 0.26%. This requirement value is similar to the dietary potassium requirement of the rat, chick and young pig.

Sodium and Potassium Effects on Adrenal-Gland Indices of Mineral Balance in Meadow Voles

We compared sodium and potassium content of plants with the dietary levels of low sodium and high potassium that stimulate hypertrophy of the zona glomerulosa of the adrenal gland of Microtus pennsylvanicus. The zona glomerulosa typically enlarges in animals subjected to severe sodium shortage or potassium overload. Among voles maintained on several low sodium diets, the relative size of the zona glomerulosa was elevated significantly only on the lowest sodium diet (0.00043 mol/kg or 10 ppm). This level of sodium is extremely low for plant sodium contents in nature. Dietary potassium levels ≥0.614 mol/kg or 24,000 ppm induced significant increases in size of zona glomerulosa; few plant species we analyzed had potassium levels below these early in the growing season. From our results, we suggest that potassium excess may play a more central role than sodium deficiency in the seasonal mineral-balance dynamics of this herbivore species.

Relation between potassium excretion and proximal tubular fluid output in conscious unoperated rats adapted to different dietary potassium contents.

The effect of dietary potassium content on the proximal tubular fluid output (Vprox), and the relation between Vprox and potassium excretion was examined in conscious unoperated diabetes insipidus rats adapted to five dietary potassium contents in the range 25-400 mmol/kg. The lithium clearance (CLi) and the urine flow (V) were used as measures of Vprox, CLi being equal to and V being about one-third of Vprox. Increase of the dietary potassium content from 25 to 400 mmol/kg led only to a slight, barely statistically significant increase of Vprox. However, repeated measurements in the same rats on different days showed considerable intraindividual variation of Vprox and the potassium excretion. At each dietary potassium level except the lowest one the potassium excretion was linearly correlated to CLi (r = 0.60-0.92) and to V (r = 0.56-0.85). Errors in bladder emptying could not explain these correlations. The slopes of the regression lines increased with increasing dietary potassium content, and the regression lines all intercepted the CLi axis at approximately the same CLi value, i.e., on the average about 70 microliter/min./100 g body weight. The results indicate that an increase of the dietary potassium content leads to a slight increase of Vprox. Spontaneous intraindividual variation of Vprox is considerable and is associated with linearly related variation of the potassium excretion. The change of the potassium excretion for a given change of Vprox increases with the dietary potassium content.

Gossypol-hypokalaemia interrelationships.

Around 1% of 8806 volunteers taking gossypol as a male contraceptive had hypokalaemic paralysis and more had simple hypokalaemia, the direct cause being renal potassium loss. In gossypol takers not showing hypokalaemia, serum potassium levels were within the normal range but were significantly lower than levels in controls. In the majority of patients suffering from gossypol-induced hypokalaemia, recovery was prompt and complete following potassium repletion, but in some men there were recurrent attacks of hypokalaemia during a period of several months to years after cessation of gossypol treatment. The incidence of hypokalaemic paralysis in gossypol takers showed distinct regional differences, being much higher in Nanjing, where the dietary potassium level of the inhabitants was low, than in Taian, where the dietary potassium level was high. In rats fed a low-K fodder, gossypol reduced the intracellular Mg and K concentrations of the skeletal muscle, while in regularly fed rats, this effect of gossypol was not observed. A potassium deficient diet could thus be considered a contributing factor in the development of gossypol-induced hypokalaemia. Potassium deficiency has also been shown to enhance the anti-spermatogenic effect of gossypol. Suggested mechanisms for the development of gossypol-induced hypokalaemia include inhibition of Na-K-ATPase activity, stimulation of prostaglandin biosynthesis, damage to the renal tubule, and modification of membrane transport.

Effects of Dietary Potassium and Race on Urinary Excretion of Kallikrein and Aldosterone in Man

Urinary excretion of kallikrein by 16 normal and 8 hypertensive subjects was studied at three levels of dietary potassium: 85 meq/day for 5 days, 185 meq/day for 7 days, and 25 meq/day for 10 days. Excretion of kallikrein varied directly with potassium intake and paralleled excretion of aldosterone in both normotensive and hypertensive subjects. Mean levels of excretion of kallikrein at 85, 185, and 25 meq intake of potassium were 10.8, 19.1, and 5.8 esterase U/day (EU/day), respectively, for the normotensive subjects and 8.8, 13.9, and 6.1 EU/day for the hypertensive subjects. Mean levels of excretion of kallikrein were significantly higher in white that in black subjects among normals and hypertensives [13.0 vs. 5.9 EU/day for normals (P less than 0.05) and 13.7 vs. 4.0 EU/day for hypertensives (P less than 0.05) on the 85 meq/day diet]. The parallel changes in excretion of kallikrein and aldosterone support the hypothesis that changes in effective levels of aldosterone induce changes in the excretion of kallikrein. Because of racial differences in excretion of kallikrein, matched groups should be used for comparisons of the kallikrein system in disease states.

Re-examination on the Potassium Requirement for Starting Chicks

Re-examination on the potassium requirement, i.e., 0.20% of dietary level which is recommended as Japanese Feeding Standard, was performed by feeding the purified diet with casein mixture as protein source to White Leghorn and meat-type chicks for three weeks. In both White Leghorn and meat-type chicks, more than 0.15% of dietary potassium level was completely preventive against chicks' mortality resulted from potassium deficiency.Potassium requirement until 1, 2, and 3 weeks of age was determined to be 0.37, 0.34, and 0.34%, respectively, for White Leghorn, and to be 0.30, 0.28, and 0.24, for meattype chicks, tending to be lowered with chick's growth. Consequently, all of the requirement until 1, 2, and 3 weeks of age were higher than 0.20%, the recommended level as Japanese Feeding Standard. Therefore, it was clarified in this experiment that 0.20% of dietary potary potassium level was insufficient for maximal growth of starting chicks. It was also revealed that there was a breed difference between White Leghorn and meat-type chicks in the potassium requirement.

Interrelationship of Dietary Vitamin D3 with Potassium, Sodium and Magnesium in Young Turkeys ,

Six experiments were conducted with Large White and Bronze turkeys to four weeks of age. The interrelationship of dietary vitamin D3 with either potassium, sodium or magnesium was studied in two experiments each. One group of 8–9 male and one group of 8–9 female poults were randomly assigned to each treatment within an experiment. The design of all experiments involved a factorial arrangement of two variables: vitamin D3 and a mineral element. For example, all possible combinations of four dietary potassium levels, 0.24, 0.34, 0.44, 0.54%; and four vitamin D3 levels 400, 800, 1600 and 3200 I.C. units/kg. were fed in the second potassium experiment. Significant (P < 0.05) weight gain differences occurred among both K levels and D3 levels in this particular experiment. Average four-week body weights were 336, 393, 382 and 430 g., respectively, for potassium levels and 330, 391, 404 and 426 g., respectively, for vitamin D3 levels. There was a significant interaction between dietary K and D3 levels relative to four-week body weight gains. Vitamin D3 tended to increase retention of both potassium and sodium in the body. A significant interaction occurred between dietary magnesium and vitamin D3 relative to body weight gain. Vitamin D3 increased magnesium content in tibiae ash and decreased magnesium content in serum.

The Response of Blood Ionic Constituents and Acid-Base Balance to Dietary Sodium, Potassium and Chloride in Laying Fowls

A 23 factorial experiment of two levels of dietary sodium × two levels of dietary chloride × two levels of dietary potassium was conducted with 72 laying hens. Arterial blood pH and plasma Na +, K +, Cl− and HCO3− were measured during shell formation. Sodium or potassium supplementation resulted in an increase, and chloride feeding resulted in a decrease in blood pH and HCO3−. Significant interactions between the dietary variables were noted with regard to blood acid-base. Dietary supplementation with each of the electrolytes resulted in an increase in its own concentration in blood plasma. Dietary sodium supplementation depressed plasma potassium concentrations whereas potassium had no consistent effect on plasma sodium. Chloride supplementation of low but not high sodium diets caused an increase in plasma sodium. Dietary sodium slightly increased plasma chloride at low levels of dietary chloride and depressed plasma chloride at high dietary chloride concentrations. Significant multiple regressions were found between sodium, chloride and bicarbonate concentrations in plasma. Plasma potassium was not correlated with any of the other monovalent ions.