International Units Of Vitamin D3 Research Articles

Genetic Variants Associated with the Biochemical Response to Vitamin D3 in the Multi-Ethnic Study of Atherosclerosis.

The response to treatment with vitamin D varies between patients. To identify genetic variants associated with the biochemical response to vitamin D3 supplementation. Randomized placebo-controlled trial conducted between 2017 and 2019. The trial was nested in an ongoing community-based cohort study, the Multi-Ethnic Study of Atherosclerosis (MESA). 2,000 International Units of vitamin D3 or placebo daily for 16 weeks. The analytic sample included 427 participants assigned to vitamin D3 (mean age 73 y, 54% females) and was 36% White, 33% Black, 18% Hispanic, and 14% Chinese. The biochemical response to vitamin D3 included changes in serum concentrations of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], parathyroid hormone (PTH), and 25-hydroxyvitamin D3 [25(OH)D3]. In genome-wide analyses, SNPs in 8 regions of the genome had significant association (p < 5E-08) with one of the traits (2 with change in 1,25(OH)2D3, 1 with change in PTH, and 5 with change in 25(OH)D3). rs16867276 within an intergenic region on 2q31 was associated with change in serum 1,25(OH)2D3 (+8.37 pg/mL difference per effect allele; p = 4.93E-08) and was the only locus that achieved genome-wide significance in transethnic meta-analysis. rs114044709 adjacent to FAM20A, which encodes a protein required for biomineralization, was associated with change in PTH among Black participants (+20.32 pg/mL difference per effect allele; p = 1.34E-08). In candidate analyses, SNPs within SULT2A1 and CYP24A1 had significant association (p < 0.05 ÷ 36 = 0.0014) with the changes in 1,25(OH)2D3 and PTH, respectively. Our results reveal potential new pathways of vitamin D regulation that require replication in other vitamin D trials.

Vitamin D supplementation and hospitalization for infection in older adults: A post-hoc analysis of data from the Australian D-Health Trial

BackgroundEvidence suggests that vitamin D influences the immune system. Recent studies indicate that vitamin D supplementation may reduce the severity of infections, but this has not been confirmed. ObjectivesThe objective of this study was to assess the effect of vitamin D supplementation on hospitalization for infection. MethodsThe D-Health Trial was a randomized, double-blind, placebo-controlled trial of monthly 60,000 international units of vitamin D3 for 5 y among 21,315 Australians aged 60–84 y. Hospitalization for infection, ascertained through linkage with hospital admitted patient data, is a tertiary outcome of the trial. The primary outcome for this post-hoc analysis was hospitalization for any infection. Secondary outcomes were extended hospitalization for infection (length of stay >3 d and >6 d) and hospitalization for respiratory tract, skin, and gastrointestinal infections. We used negative binomial regression to estimate the effect of vitamin D supplementation on outcomes. ResultsParticipants (46% women, mean age: 69 y), were followed up for a median of 5 y. Vitamin D supplementation had little or no effect on the incidence of hospitalization for any infection [incidence rate ratio (IRR): 0.95; 95% CI: 0.86, 1.05], respiratory tract (IRR: 0.93; 95% CI: 0.81, 1.08), skin (IRR: 0.95; 95% CI: 0.76, 1.20), gastrointestinal infections (IRR: 1.03; 95% CI: 0.84, 1.26), or hospitalizations lasting >3 d (IRR: 0.94; 95% CI: 0.81, 1.09), with all CIs consistent with a null finding. People supplemented with vitamin D had fewer hospitalizations lasting >6 d (IRR: 0.80; 95% CI: 0.65, 0.99). ConclusionsWe did not find a protective effect of vitamin D on hospitalization for infection, but it reduced the number of extended hospitalizations. In populations where few people are vitamin D deficient, the effect of population-wide supplementation is likely to be small, but these findings support previous studies suggesting that vitamin D plays a role in infectious disease.The D-Health Trial is registered at the Australian New Zealand Clinical Trials Registry as ACTRN12613000743763.

Serum Vitamin D: Correlates of Baseline Concentration and Response to Supplementation in VITAL-DKD.

The effect of daily vitamin D supplementation on the serum concentration of vitamin D (the parent compound) may offer insight into vitamin D disposition. To assess the total serum vitamin D response to vitamin D3 supplementation and whether it varies according to participant characteristics. To compare results with corresponding results for total serum 25-hydroxyvitamin D [25(OH)D], which is used clinically and measured in supplementation trials. Exploratory study within a randomized trial. 2000 International Units of vitamin D3 per day (or matching placebo). Community-based. 161 adults (mean ± SD age 70 ± 6 years; 66% males) with type 2 diabetes. Changes in total serum vitamin D and total serum 25(OH)D concentrations from baseline to year 2. At baseline, there was a positive, nonlinear relation between total serum vitamin D and total serum 25(OH)D concentrations. Adjusted effects of supplementation were a 29.2 (95% CI: 24.3, 34.1) nmol/L increase in serum vitamin D and a 33.4 (95% CI: 27.7, 39.2) nmol/L increase in serum 25(OH)D. Among those with baseline 25(OH)D < 50 compared with ≥ 50 nmol/L, the serum vitamin D response to supplementation was attenuated (15.7 vs 31.2 nmol/L; interaction P-value = 0.02), whereas the serum 25(OH)D response was augmented (47.9 vs 30.7 nmol/L; interaction P-value = 0.05). Vitamin D3 supplementation increases total serum vitamin D and 25(OH)D concentrations with variation according to baseline 25(OH)D, which suggests that 25-hydroxylation of vitamin D3 is more efficient when serum 25(OH)D concentration is low.

25-OHD response to vitamin D supplementation in children: effect of dose but not GC haplotype.

GC/DBP effects on response to vitamin D supplementation have not been well-studied. Thus we assessed free and total 25-OHD after vitamin D treatment across the six common GC haplotypes. This double-blind, randomized study compared two vitamin D3 doses in healthy, urban-dwelling 6-month to 10-year-old children at-risk for vitamin D deficiency. Randomization was stratified by GC haplotype. Children were randomized to receive 2800 or 7000 International Units of vitamin D3 weekly. 25-OHD and 1,25(OH)2D were sampled at baseline and after 1-6 months of supplementation. One hundred ninety-two of 225 enrolled subjects completed the study. After one month, total 25-OHD increased with both doses and were higher with 7000 IU/week (85.5 ± 22.8 nmol/L) compared to 2800 IU/week (76.8 ± 18.0 nmol/L), despite equivalent baseline levels. No further significant increase occurred at 6 months (89.8 ± 35.5 and 74.3 ± 18.3 nmol/L, respectively). Free 25-OHD similarly changed. 25-OHD differed among GC groups at baseline. Although no significant effects of individual GC haplotypes on incremental changes were evident, a trend toward an effect of combined 'at risk' GC alleles on response was evident (P = 0.06). Total 1,25(OH)2D showed modest increases, moreso with the larger dose. In urban-dwelling children at-risk for vitamin D deficiency, 1 month of vitamin D3 2800 IU/week increased 25-OHD across all GC haplotype groups, and somewhat enhanced with 7000 IU/week with no further significant increases after 6 months of supplementation. Free 25-OHD measures offer no monitoring advantage over total 25-OHD.

Treatment with Vitamin D3 in Vitamin D Deficient Adolescents: A Pilot Study.

Multiple epidemiological studies have shown that vitamin D deficiency is highly prevalent amongst adolescents in the USA. However, recommendations regarding the treatment of vitamin D deficiency in healthy adolescents are not well defined. We carried out a prospective pilot study, to determine whether treatment with 2000 international units of vitamin D3 daily for 3 months, would normalize the vitamin D levels in vitamin D deficient adolescents. Following treatment there was a 56.02% increase in the vitamin D levels from the mean baseline values and 80.39% of the subjects normalized their vitamin D levels. There were no adverse effects associated with this intervention. This study offers complementary guidelines to the existing recommendations from the American Academy of Pediatrics on the optimal dose and duration of vitamin D3 therapy in vitamin D deficient, but otherwise healthy adolescents. Further prospective, large scale, case control studies are indicated to validate our results.

Supplementing pasteurized waste-milk with vitamins A, D, and E improves vitamin status of dairy calves

Holstein calves fed pasteurized waste milk were blocked by sex and randomly assigned to 1 of 3 treatment groups, control with no vitamin supplementation (CON, n = 18) and 2 levels of an oral vitamins A, D, and E supplement: 0.25 mL/d of supplement (0.25ADE, n = 12) or 0.5 mL/d of supplement (0.5ADE, n = 10). The supplemented calves also received a 5 mL subcutaneous injection of vitamins A, D, and E at birth. The oral and injectable supplements contained 50,000 international units (IU) of vitamin A as retinyl-palmitate, 50,000 IU of vitamin D3, and 500 IU of vitamin E as RRR-α-tocopherol per milliliter of product. Concentrations of 25-hydroxyvitamin D and a-tocopherol, but not retinol, in serum of 0.25ADE and 0.5ADE calves were greater than CON calves. We observed that supplemented calves gained less weight compared with CON calves in the first 28 d; however, height and starter grain intakes did not differ among treatments. Incidence of respiratory infection or diarrhea did not differ among groups. In conclusion, injection plus supplementation of pasteurized waste milk with vitamins A, D, and E increased concentrations of 25(OH)D and a-tocopherol in serum but decreased body weight gain, due possibly to over-supplementation of the vitamins.

Vitamin D for the Immune System in Cystic Fibrosis (DISC): a double-blind, multicenter, randomized, placebo-controlled clinical trial

Patients with cystic fibrosis (CF) have increased risk of vitamin D deficiency owing to fat malabsorption and other factors. Vitamin D deficiency has been associated with increased risk of pulmonary exacerbations of CF. The primary objective of this study was to examine the impact of a single high-dose bolus of vitamin D3 followed by maintenance treatment given to adults with CF during an acute pulmonary exacerbation on future recurrence of pulmonary exacerbations. This was a multicenter, double-blind, placebo-controlled, intent-to-treat clinical trial. Subjects with CF were randomly assigned to oral vitamin D3 given as a single dose of 250,000 International Units (IU) or to placebo within 72 h of hospital admission for an acute pulmonary exacerbation, followed by 50,000 IU of vitamin D3 or an identically matched placebo pill taken orally every other week starting at 3 mo after random assignment. The primary outcome was the composite endpoint of the time to next pulmonary exacerbation or death within 1 y. The secondary outcomes included circulating concentrations of the antimicrobial peptide cathelicidin and recovery of lung function as assessed by the percentage of predicted forced expiratory volume in 1 s (FEV1%). A total of 91 subjects were enrolled in the study. There were no differences between the vitamin D3 and placebo groups in time to next pulmonary exacerbation or death at 1 y. In addition, there were no differences in serial recovery of lung function after pulmonary exacerbation by FEV1% or in serial concentrations of plasma cathelicidin. Vitamin D3 initially given at the time of pulmonary exacerbation of CF did not alter the time to the next pulmonary exacerbation, 12-mo mortality, serial lung function, or serial plasma cathelicidin concentrations. This trial was registered at clinicaltrials.gov as NCT01426256.

Cross-sectional analysis of universal vitamin D supplementation in former East Germany during the first year of life.

Universal vitamin D supplementation is controversial. Preventative examinations and public health initiatives in former East Germany that included vitamin D prophylaxis for children were regulated by official recommendations and guidelines. The aim of this study is to analyse the impact of a standardised nationwide guideline for universal supplementation with 400 International Units (IU) vitamin D3/day during the first year of life on clinical and biochemical parameters and the influence of surrounding factors. This is a cross-sectional analysis looking at data from a field study of 3481 term-born children during their first year of life that was conducted in 1989. There were no significant clinical signs of rickets. 25 hydroxyvitamin D (25(OH)D) (mean and SEM, total analyses n=572) after birth (n=28) was 36(7) nmol/L, at 1 month 64(4) nmol/L (n=70, p<0.0001), 91(5) nmol/L at 3 months (n=95, p<0.0001), 65(8) nmol/L at 8 months (n=21, p=0.005) and ranged between 33 and 109 nmol/L until 12 months. Less than 0.2% of analyses revealed pathological levels for calcium or phosphate. Alkaline phosphatase (ALP) levels (n=690) were >1500 U/L (95th percentile) in 3.6%. Participants were on breastmilk or vitamin D-free formula, with solids added from 6 months of age. There were seasonal variations in 25(OH)D levels with a rise during spring and autumn. Thus this analysis is unique as sun exposure and supplementation can be considered as the only vitamin D sources. We conclude that universal supplementation with 400 IU of vitamin D3 during the first year of life is safe and provides sufficient 25(OH)D levels in Germany.

Effects of Vitamin D Supplementation on Serum 25-Hydroxyvitamin D Concentrations in Cirrhotic Patients: A Randomized Controlled Trial.

Background: The liver is crucial for 25-hydroxyvitamin D (25(OH)D) metabolism, and vitamin D deficiency is highly prevalent in patients with cirrhosis and predicts adverse outcomes. We aimed to evaluate whether vitamin D supplementation in patients with cirrhosis is effective in increasing 25(OH)D serum concentrations. Secondary outcome measures included liver function tests (aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (GGT), and alkaline phosphatase (AP)), albumin, International Normalized Ratio (INR), bilirubin, the liver fibrosis marker hyaluronic acid, and parameters of mineral metabolism including parathyroid hormone (PTH). Methods: This is a double-center, double-blind, placebo-controlled study conducted from December 2013 to May 2014 at the Medical University of Graz, and the hospital Hoergas-Enzenbach, Austria. We enrolled 36 consecutive patients with cirrhosis and 25(OH)D concentrations below 30 ng/mL. Study participants were randomly allocated to receive either 2800 International Units of vitamin D3 per day as oily drops (n = 18) or placebo (n = 18) for 8 weeks. Results: Thirty-three study participants (mean (SD) age: 60 (9) years; 21% females; 25(OH)D: 15.6 (7.4) ng/mL) completed the trial. The mean treatment effect (95% CI) for 25(OH)D was 15.2 (8.0 to 22.4) ng/mL (p < 0.001). There was no significant effect on any secondary outcome. Conclusions: In this randomized controlled trial, vitamin D supplementation increases 25(OH)D serum concentrations, even in cirrhotic patients.

Effect of Nandrolone, Calcium-D and Vitamin C on Fracture Union

Background: Delay union and nonunion is one of the most common fractures complications of extremities in humans. There are several factors influencing normal process of bone union. Nutrition is an important factor in this process. Objectives: In this study we aimed to observe the effect of nandrolone, calcium-D and vitamin C on the process of healing of fractures. Patients and Methods: This study included 139 male patients, aged 18 to 50 years, with fracture of the shaft of tibia and fibula that were treated surgically with intramedullary nailing. These patients were randomly divided to four groups; group 1 received 25 mg of nandrolone decanoate via intramuscular injection every three weeks. Patients of group 2 received 1000 mg of calcium carbonate plus 400 international units of vitamin D3 per day. Patients of group 3 received 1000 mg of vitamin C per day, and group 4 served as the control group and didn’t receive any drug. These groups were compared according to radiographic and clinical criteria for fracture union. Results: Patients in the nandrolone group showed better union in the first three months after surgery than the control group, with the difference being significant. There was no significant difference in calcium-D and vitamin C groups with respect to the control group. Conclusions: Nandrolone in the first three months after surgery can accelerate fracture union yet calcium plus vitamin D or vitamin C has no effect on fracture union.

Vitamin D supplementation efficacy: sleeve gastrectomy versus gastric bypass surgery.

Vitamin D deficiency is common with bariatric surgery, and few prospective studies comparing different surgical procedures have evaluated appropriate vitamin D supplementation levels. Therefore, vitamin D3 and calcium supplementation were evaluated following gastric bypass and sleeve gastrectomy. Women consumed 2,000 international units (IU) of vitamin D3 and 1,500 mg calcium citrate daily for 3 months following gastric bypass (n=11) and sleeve gastrectomy (n=12). Height, weight, body mass index (BMI), serum 25-hydroxyvitamin D [25(OH)D], and serum PTH concentrations were measured preoperatively and at 3 months. Wilcoxon signed rank analyses compared body weight parameters, serum 25(OH)D and PTH concentrations, and dietary intakes of vitamin D and calcium preoperatively and at 3 months. Vitamin D deficiency was defined as a serum 25(OH)D concentration <20 ng/mL (50 nmol/L). Vitamin D deficiency decreased from 60.6 % preoperatively to 26.1 % after 3 months (P<0.005). Serum 25(OH)D concentrations increased an average of 8 ng/mL (P<0.001), and PTH concentrations decreased an average of 9 ng/L, although reductions were not significant. Overall, the response to supplementation following gastric bypass and sleeve gastrectomy did not differ. Reduced food intake increased the risk of vitamin D deficiency following bariatric surgery. However, daily supplementation with 2,000 IU of vitamin D3 and 1,500 mg calcium citrate significantly increased 25(OH)D concentrations and reduced the percent of women who were vitamin D deficient. Although serum 25(OH)D concentrations did not reach levels associated with detrimental health effects, several women remained vitamin D deficient and more aggressive supplementation may be indicated.

Incidence of milk alkali syndrome in the Women's Health Initiative clinical trial and cohort study: response to Neupane

Dear Editor, We thank Dr. Neupane for her letter [1] on our report on calcium and vitamin D supplementation in the Women's Health Initiative (WHI) [2]. Though we did not collect information on the incidence of the rather common milk alkali syndrome, women in the WHI calcium plus vitamin D (CaD) randomized trial were queried twice a year, during the average 7-year intervention period, concerning the occurrence of hypercalcemia and concerning the initiation of kidney dialysis. A total of 51 intervention group and 52 placebo group women reported initiating dialysis during trial follow-up. Our regression analyses that stratify on 5-year baseline age, on randomization assignment in the WHI Hormone Therapy (HT) and Dietary Modification (DM) trials, and on baseline history of kidney stones yield a kidney dialysis hazard ratio (95 % confidence interval) of 0.98 (0.66, 1.44), with no evidence (p=0.72) of interaction with personal supplement use. In comparison, incident hypercalcemia was reported by 422 intervention group women compared to 245 placebo group women. The hypercalcemia HR (95 % CI) was 1.73 (1.47, 2.02) from Cox regression analyses that stratified on baseline age, HTand DM randomization group, and baseline history of hypercalcemia. The HR (95 % CI) was 1.83 (1.39, 2.39) among women not taking personal calcium or vitamin D supplements and 1.69 (1.39, 2.06) among personal supplement users. Censoring the follow-up period when a woman first becomes nonadherent to her assigned study pills gives a hypercalcemia HR (95 % CI) of 1.79 (1.45, 2.21). In summary, the 1,000 mg calcium carbonate plus 400 international units of vitamin D3 studied in the WHI clinical trial evidently increases the incidence of hypercalcemia and, as previously reported, kidney stone occurrence, but did not increase the risk of kidney dialysis during trial follow-up.

Expression of 1alpha-HYD and 24-HYD in bovine kidney mediated by vitamin D3 supplementation

In order to better understand vitamin D3 in cattle metabolism, we quantified 1alpha-HYD and 24-HYD gene expression. In the kidneys of 35 male Nellore cattle, these were divided into a control group and two treatment groups (2 x 10(6) international units of vitamin D3 administered for 2 or 8 consecutive days pre-slaughter). Vitamin D3 supplementation resulted in a significant increase in 1alpha-HYD gene expression; however, significantly increased 24-HYD gene expression was only detected in cattle that had 8 days of supplementation. The finding of upregulation of 24-HYD due to vitamin D supplementation is in line with the expected rise in 24,25-di-hydroxy-vitamin D3 synthesis observed when plasma vitamin D3 concentrations are high, stimulating excretion by the organism. On the other hand, upregulation of 1alpha-HYD was unexpected, since vitamin D3 supplementation has been reported to impact these two genes in opposite directions. We conclude that vitamin D3 metabolism in these animals is more complex than previously reported.

Dietary Vitamin D Exposure Prevents Obesity-Induced Increase in Endometrial Cancer inPten+/−Mice

The possibility that dietary vitamin D(3) (VD(3)) exposure inhibits endometrial carcinogenesis in an animal model and modifies the enhanced risk of endometrial carcinoma associated with obesity was investigated. At 4 weeks of age, Pten(+/-) and wild-type mice were each divided into four treatment groups and fed AIN93G control diet, or AIN93G-based diet containing either 25,000 international units of VD(3) per kilogram of diet, 58% fat to induce obesity (high fat), or high fat and 25,000 international units of VD(3) per kilogram of diet. Mice were kept on these diets until they were sacrificed at week 28. Although VD(3) did not affect endometrial cancer risk, it inhibited obesity-induced increase in endometrial lesions. Specifically, high-fat diet increased focal glandular hyperplasia with atypia and malignant lesions from 58% in the control diet-fed Pten(+/-) mice to 78% in obese mice. Dietary VD(3) decreased the incidence of endometrial pathology in obese Pten(+/-) mice to 25% (P < 0.001). VD(3) altered the endometrial expression of 25-hydroxylase, 1α-hydroxylase, and vitamin D receptor in the wild-type and Pten(+/-) mice. Estrogen receptor-α mRNA levels were higher (P < 0.014) and progesterone receptor protein levels in the luminal epithelium were lower (P < 0.04) in the endometrium of control diet-fed Pten(+/-) than wild-type mice, but the expression of these receptors was not affected by the dietary exposures. VD(3) reversed the obesity-induced increase in osteopontin (P < 0.001) and significantly increased E-cadherin expression (P < 0.019) in the endometrium of obese Pten(+/-) mice. Our data confirm the known association between obesity and endometrial cancer risk. Dietary exposure to VD(3) inhibited the carcinogenic effect of obesity on the endometrium. This protective effect was linked to a reduction in the expression of osteopontin and increase in E-cadherin.

Calcium and Vitamin D Supplementation for the Prevention of Fractures in Postmenopausal Women

Evaluation of: Jackson RD, LaCroix AZ, Gass M et al.: Calcium plus vitamin D supplementation and the risk of fractures. N. Engl. J. Med. 352, 669–683 (2006) [1] . This randomized, controlled trial compared the use of 1000 mg of elemental calcium with 400 international units of vitamin D3 daily versus placebo in postmenopausal women aged 50–79 years enrolled in the Women’s Health Initiative trial. The follow-up period averaged approximately 7 years. In the active-treatment group, there was a small but statistically significant increase in hip-bone density, but no reduction in the overall rate of hip fracture (primary outcome) compared with the placebo group. Calcium and vitamin D3 appeared to be well tolerated, but there was an increased risk of kidney stones in women receiving treatment.

Parvalbumin increases in the caudate putamen of rats with vitamin D hypervitaminosis.

The influence of chronic vitamin D3 application on the concentration of the four calcium-binding proteins parvalbumin, the 28-kDa calbindin-D, calmodulin, and S-100 was studied in various brain regions and in the kidney. Young rats were administered daily 20,000 international units of vitamin D3 per kg (body weight) over a period of 4 months. This chronic treatment resulted in a clinically mild hypervitaminosis that did not affect the content of calmodulin, the 28-kDa calbindin-D, and S-100. Also the concentration of parvalbumin in the cerebral cortex, hippocampus, and kidney remained unchanged. On the other hand, parvalbumin was increased about 50% in the caudate putamen of hypervitaminotic animals as compared to controls. Our results indicate that the metabolism of parvalbumin in the caudate putamen can be influenced by variations of the blood level of this steroid hormone.

Regulation of brain and cerebrospinal fluid calcium by brain barrier membranes following vitamin D-related chronic hypo- and hypercalcemia in rats.

Male Fischer-344 rats, 21 days old, were fed diets containing 0 (LOD), 2,200 (CONT), or 440,000 (HID) international units of vitamin D3 per kilogram for 12 weeks. [Ca] was measured in plasma, CSF, brain, and choroid plexus. In addition, 45Ca and 36Cl transfer coefficients (KCa and KCl) for uptake from blood into CSF and brain were determined. Although plasma ionized [Ca]s in LOD and HID rats were 50% and 136%, respectively, of values in CONT animals, CSF and brain [Ca]s ranged from only 85% to 110% of respective CONT values. Choroid plexus [Ca] was increased by 37% after HID diet, but was decreased only 10% after LOD. KCa values at CSF, parietal cortex, and pons-medulla were negatively correlated with plasma ionized [Ca], whereas KCl values at CSF and brain were not different between the diet groups. The findings demonstrate that central nervous system [Ca] is maintained during chronic hypo- or hypercalcemia by saturable transport of Ca at brain barrier membranes. This transport does not seem to involve modulation by 1,25-dihydroxyvitamin D3.

Influence of Maternal Vitamin D Intake on Growth and Bone Ash of Offspring

In view of reports that have appeared in the daily press claiming damage to human offspring as a result of maternal overdoses of vitamin D, it was considered of interest to observe offspring of hens fed high doses of this vitamin. Three groups of five Leghorn hens and one cock each were given a commercial laying ration providing either 660, 6600, or 66,000 International Units of vitamin D3 per kg. The hens were trapnested over a period of 3 months, and all eggs collected from the nests were incubated at 2-week intervals. The chicks obtained from the third to sixth hatch were grown to 5 weeks of age on a starter diet devoid of vitamin D3; their weights were recorded weekly. In one instance the chicks hatching from eggs laid on the floor rather than in the nests were grown on a starter diet supplemented with vitamin D3. Thirty chicks …