Effects of 25-hydroxycholecalciferol supplementation in maternal diets on reproductive performance and the expression of genes that regulate lactation in sows.

One hundred Yorkshire × Landrace sows were randomly assigned to one of two dietary treatments (diet ND: 6,000 IU vitamin D3 /d feed; diet 25-D: 200 µg/day 25OHD3 feed). The experiment began on d 90 of gestation and continued until weaning on day 21 of lactation. In sows that received 25OHD3 , the growth rate of the piglets before weaning was significantly accelerated (0.266 kg/day, p < .05). Sow serum was collected after weaning, and those in the 25OHD3 group were found to have significantly higher serum calcium (CA) and phosphorus (PI) levels (p < .05). Interestingly, the oestrus cycle of sows fed 25OHD3 was significantly shortened (p < .05), the oestrus time was concentrated on the fifth day after weaning, and the piglets were born with a higher degree of uniformity (p < .05). Colostrum was collected on the day of delivery, and the colostrum of sows fed 25OHD3 contained higher milk fat content than the control group (p < .05). 25OHD3 supplementation increased the mRNA and protein expression of INSIG1 and SREBP1, which regulate milk fat synthesis, in the mammary gland of lactating sows (p < .05). In conclusion, 25OHD3 supplementation in maternal diets improved reproductive performance, milk fat content and the mRNA and protein levels of genes regulating milk fat synthesis in lactating sows.

Italian Association of Clinical Endocrinologists (AME) and Italian Chapter of the American Association of Clinical Endocrinologists (AACE) Position Statement: Clinical Management of Vitamin D Deficiency in Adults

Vitamin D deficiency is very common and prescriptions of both assay and supplementation are increasing more and more. Health expenditure is exponentially increasing, thus it is timely and appropriate to establish rules. The Italian Association of Clinical Endocrinologists appointed a task force to review literature about vitamin D deficiency in adults. Four topics were identified as worthy for the practicing clinicians. For each topic recommendations based on scientific evidence and clinical practice were issued according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) System. (1) What cut-off defines vitamin D deficiency: even though 20 ng/mL (50 nmol/L) can be considered appropriate in the general population, we recommend to maintain levels above 30 ng/mL (75 nmol/L) in categories at risk. (2) Whom, when, and how to perform screening for vitamin D deficiency: categories at risk (patients with bone, liver, kidney diseases, obesity, malabsorption, during pregnancy and lactation, some elderly) but not healthy people should be screened by the 25-hydroxy-vitamin D assay. (3) Whom and how to treat vitamin D deficiency: beyond healthy lifestyle (mostly sun exposure), we recommend oral vitamin D (vitamin D2 or vitamin D3) supplementation in patients treated with bone active drugs and in those with demonstrated deficiency. Dosages, molecules and modalities of administration can be profitably individually tailored. (4) How to monitor the efficacy of treatment with vitamin D: no routine monitoring is suggested during vitamin D treatment due to its large therapeutic index. In particular conditions, 25-hydroxy-vitamin D can be assayed after at least a 6-month treatment. We are confident that this document will help practicing clinicians in their daily clinical practice.

Comparison of two methods for measuring 25-OH vitamin D in the follow-up of patients after bilio-pancreatic diversion bariatric surgery.

OBJECTIVE: Our objective was to compare the ECLIA from Roche versus the LC-MS/MS method for quantitation of serum 25-hydroxy-vitamin D in patients who have undergone bariatric surgery. DESIGN AND METHODS: Cross-sectional and correlational studies were performed on three different groups for the 25-OH-D levels quantitated by both methods. The control group of apparently healthy subjects was randomly selected in a clinical chemistry laboratory. Test groups were patients who had undergone bilio-pancreatic diversion (BPD) and were supplemented either with vitamin D2 or with vitamin D3. The number of samples per group was established according to the CLSI recommendation protocol (EPO9-A2-IR). RESULTS: The agreement of LC-MS/MS with the Roche method was acceptable in the apparently healthy subjects group and in the post-BPD D3-supplemented group with an average bias of -1.7% and -9.2%, respectively. However, this agreement was unacceptable in the post-BPD D2-supplemented group with an average bias of -45.3%. The LC-MS/MS enabled us to detect four patients who had excess vitamin D or poisoning with vitamin D for which it was necessary to stop the supplementation with vitamin D in the D2 -supplemented group. CONCLUSION: Despite the apparent good agreement between the Roche method and LC-MS/MS in the healthy subjects group and in the post-DBP D3-supplemented patient group, a considerable bias seems to exist, particularly in the presence of D2. The LC-MS/MS method is therefore the most accurate method to follow the vitamin D2 -supplemented bariatric population.

Treatment of vitamin D deficiency: divergence between clinical practice and expert advice.

BACKGROUND: Current recommendations for the treatment of vitamin D deficiency vary from calciferol 800 IU per day to loading doses of vitamin D followed by maintenance therapy of up to 2000 IU per day. OBJECTIVE: To assess the preparations and doses of vitamin D used to load and maintain patients with serum 25-hydroxyvitamin D (25OHD) <25 nmol/l. METHODS: We examined all requests for serum 25OHD over a 12-month period, from September 2009 to 2010 in southwest Scotland. We wrote to all 33 general practices asking whether they usually started replacement therapy with a loading dose and/or recommended over-the-counter maintenance preparations. We accessed the Emergency Care Summary for all patients with serum 25OHD <25 nmol/l to determine whether they had been prescribed maintenance therapy. RESULTS: Serum 25OHD was requested in 1162 patients. Levels were <25 nmol/l in 282 (24%) patients, only 173 (61%) of whom were receiving vitamin D replacement therapy 3-15 months after diagnosis. Only four (1.4%) were prescribed a loading dose. One hundred and fifty-three (54%) were treated with cholecalciferol or ergocalciferol and 19 (7%) with alfacalcidol or calcitriol. The median dose of chole/ergocalciferol was 800 IU per day, usually in combination with 1200 mg calcium per day. CONCLUSIONS: We have shown a divergence between clinical practice and even the most conservative expert advice for vitamin D replacement therapy. Possible explanations are conflicting advice on treatment and difficulty obtaining suitable vitamin D preparations, particularly high dose vitamin D and vitamin D without calcium, in the UK.

Selective monitoring of vitamin D2 and D3 supplementation with a highly specific 25-hydroxyvitamin D3 immunoassay with negligible cross-reactivity to 25-hydroxyvitamin D2.

BACKGROUND: The effects of vitamin D2 and D3 supplementation on circulating concentrations of 25(OH)D3 require reliable analytical tools for specific determination of 25(OH)D3 and 25(OH)D2. We have developed a highly specific 25-OH Vitamin D3 ELISA with negligible cross-reactivity towards 25(OH)D2. METHODS: 25(OH)D3 concentrations were measured in several study participants; 1) 641 healthy men and women; 2) 39 postmenopausal women receiving 400-800 IU vitamin D3 daily for 4 months; 3) 45 men and women with hip fracture receiving 1000 IU vitamin D2 daily for 3 months. RESULTS: This 25-OH Vitamin D3 ELISA had minimal cross-reactivity to 25(OH)D2, (0.7%), and demonstrated a high correlation (r2 = 0.93) with 25(OH)D3 determined by HPLC. 25(OH)D3 increased by 14% in subjects receiving vitamin D3 for 4 months (p < 0.01), whereas there was no significant change in 25(OH)D3 levels in those receiving vitamin D2. CONCLUSIONS: We report that 25(OH)D3 ELISA was used for evaluation of 25(OH)D3 concentrations in subjects receiving vitamin D2 and D3 supplementation. The increase of 25(OH)D3 in circulation with vitamin D3 supplementation and lack of increase with vitamin D2 supplementation suggest that this assay has sufficient sensitivity and specificity to be used as a reliable measurement of nutritional vitamin D3 status in humans.

Secondary hyperparathyroidism in primary osteoporosis and osteopenia: optimizing calcium and vitamin D intakes to levels recommended by expert panels may not be sufficient for correction.

OBJECTIVE: To compare biochemical variables, renal function and calcium and vitamin D intakes in euparathyroid and hyperparathyroid patients with primary osteoporosis and osteopenia and describe the measures necessary to normalize serum PTH in the patients with secondary hyperparathyroidism. DESIGN AND PATIENTS: We reviewed the charts of normocalcemic patients with primary osteoporosis and osteopenia first seen during the years 1991-2003 and identified 75 with elevated serum PTH levels at baseline. These patients were compared to all the 143 euparathyroid patients first seen in 1998 and 1999. Patients were restudied after 1 year and we attempted to follow patients with secondary hyperparathyroidism until PTH levels became normal. MEASUREMENTS: At baseline serum PTH, ionized calcium, inorganic phosphate, alkaline phosphatase, creatinine, a complete blood count and serum 25 hydroxy vitamin D were measured in the early morning fasting state. These tests were repeated at follow up. RESULTS: In one-third of the hyperparathyroid patients, the standard baseline treatment failed to correct the secondary hyperparathyroidism necessitating extraordinary measures including unusually large doses of vitamin D (i.e. 50 000 IU vitamin D(2) twice weekly) or the substitution of calcium citrate for calcium carbonate as a calcium supplement. CONCLUSION: Large doses of vitamin D are frequently necessary to suppress secondary hyperparathyroidism in patients with primary osteoporosis and osteopenia. This suggests that vitamin D metabolism may be altered in some of these patients.

Vitamin D improves endothelial function in patients with Type 2 diabetes mellitus and low vitamin D levels.

AIMS: To test whether a single large dose of vitamin D2 can improve endothelial function in patients with Type 2 diabetes mellitus and low serum 25-hydroxyvitamin D levels. METHODS: Double-blind, parallel group, placebo-controlled randomized trial. A single dose of 100,000 IU vitamin D2 or placebo was administered to patients with Type 2 diabetes over the winter, when levels of circulating 25-hydroxyvitamin D were likely to be lowest. Patients were enrolled if their baseline 25-hydroxyvitamin D level was < 50 nmol/l. Endothelial function and blood pressure were measured and fasting blood samples were taken at baseline and 8 weeks after administration of vitamin D. RESULTS: Forty-nine per cent of subjects screened had 25-hydroxyvitamin D levels < 50 nmol/l. Thirty-four subjects completed the study, with a mean age of 64 years and a baseline 25-hydroxyvitamin D level of 38.3 nmol/l. Vitamin D supplementation increased 25-hydroxyvitamin D levels by 15.3 nmol/l relative to placebo and significantly improved flow mediated vasodilatation (FMD) of the brachial artery by 2.3%. The improvement in FMD remained significant after adjusting for changes in blood pressure. Vitamin D supplementation significantly decreased systolic blood pressure by 14 mmHg compared with placebo; this did not correlate with change in FMD. CONCLUSIONS: Vitamin D insufficiency is common in patients with Type 2 diabetes during winter in Scotland. A single large dose of oral vitamin D2 improves endothelial function in patients with Type 2 diabetes and vitamin D insufficiency.