Vitamin D supplementation

Animals exposed to sunlight for extended lengths of time do not require substantial dietary vitamin D. Current livestock management practices place an emphasis on high productivity, and most feed manufacturers recommend vitamin D supplementation of diets. Recommendations for practical levels of vitamin D in feeds for various animals, as recommended by feed manufacturers, are listed in Table 10. 

Parathyroidectomy is a treatment of last resort for sHPT, but should be considered in patients with persistently elevated iPTH levels above 800 pg/mL (800 ng/L) that is refractory to medical therapy to lower serum calcium and/or phosphorus levels.39 A portion or all of the parathyroid tissue may be removed, and in some cases a portion of the parathyroid tissue may be transplanted into another site, usually the forearm. Bone turnover can be disrupted in patients undergoing parathyroidectomy whereby bone production outweighs bone resorption. The syndrome, known as hungry bone syndrome, is characterized by excessive uptake of calcium, phosphorus, and magnesium for bone production, leading to hypocalcemia, hypophosphatemia, and hypomagnesemia. Serum ionized calcium levels should be monitored frequently (every 4 to 6 hours for the first 48 to 72 hours) in patients receiving a parathyroidectomy. Calcium supplementation is usually necessary, administered IV initially, then orally (with vitamin D supplementation) once normal calcium levels are attained for several weeks to months after the procedure. 

Adequate calcium and vitamin D intake is essential in the prevention and treatment of osteoporosis. Calcium and vitamin D supplements to meet requirements should be added to all drug therapy regimens for osteoporosis. 

Calcium and vitamin D supplementation increases bone mineral density, and the combination decreases the risk of hip and vertebral fractures. Additionally, vitamin D supplementation decreases nonvertebral fractures in older men and women living independently.11 Because of the effects of calcium on... 

Daily calcium and vitamin D requirements are highest in postmenopausal women and elderly men 1500 mg elemental calcium and 400 to 800 IU vitamin D (see Table 53-4). When these requirements cannot be achieved by diet alone, appropriate calcium and/or vitamin D supplementation is recommended. 

Pay special attention to any vitamins and calcium and vitamin D supplements the patient is taking. 

Recommend appropriate calcium and vitamin D supplementation (see Table 53-6). 

Home hazard assessment and modification Withdrawal of psychotropic medication Nutritional supplements Vitamin D supplements... 

The GP made a provisional diagnosis of osteomalacia and prescribed vitamin D supplements. Vitamin D measurements are not performed routinely, but the assumption is that a low result would have been obtained on the blood sample. Most of the vitamin D necessary to maintain normal calcium homeostasis is derived from endogenous synthesis by reactions in the skin (which require UV radiation from sunlight), liver and kidney. The cultural habits of Mrs Al-Ameri required her to dress in a burqah and niqab whenever she left the home, meaning that very little of her skin was exposed to daylight. 

Calcium/Vitamin D supplementation Patients should receive supplemental calcium if dietary intake is inadequate. Patients at increased risk for vitamin D insufficiency (eg, those in nursing homes, chronically ill, older than 70 years of age), should receive vitamin D supplementation in addition to that provided in alendronate/cholecalciferol. Patients with Gl malabsorption syndromes may require higher doses of vitamin D supplementation consider measurement of 25-hydroxyvitamin D. 

Bischoff-Ferrari, H. A., Willet, W. C., Wong, J. B., Giovarmucci, E., Dietrich, T., and Dawson-Hughes, B. (2005). Fracture prevention with vitamin D supplementation A meta-analysis of randomized controlled trials. JAMA 293, 2257-2264. 

Boonen, S., Lips, P., Bouillon, R., Bischoff-Ferrari, H. A., Vanderschueren, D., and Haentjens, P. (2007). Need for additional calcium to reduce the risk of hip fracture with vitamin D supplementation Evidence from a comparative meta-analysis of randomized controlled trials. J. Clin. Endocrinol. Metab. 92,1415-1423. 

Effect of vitamin D supplementation on wintertime and overall bone loss in healthy postmenopausal women. Ann. Intern. Med. 115, 505-512. 

Dawson-Hughes, B., Harris, S. S., Krall, E. A., and Dallal, G. E. (2000). Effect of withdrawal of calcium and vitamin D supplements on bone mass in elderly men and women. Am. ]. Clin. Nutr. Tl, 745-750. 

She should be encouraged to take calcium and vitamin D supplementation immediately. She should be scheduled for baseline determination of her bone density so that any evidence of loss of bone mass can be ascertained. 

Clinical trials have demonstrated that the use of the bisphosphonates, nasal calcitonin, or human rPTH combined with calcium and vitamin D supplementation is effective in preventing drug-induced osteoporosis. Thus, individuals receiving over the long term any medication that can induce osteomalacia should also take one of these compounds and have periodic bone density determinations. 

D. There is no evidence that affinity for D3 with its receptor is altered during aging. Aging is associated with vitamin D deficiency for several reasons. It is important for the elderly to receive vitamin D supplementation to prevent osteoporosis and the other problems associated with hypocalcemia. If they have chronic liver or renal conditions, use of one of the specific metabolites should be used, such as cal-citriol. 

Geriatric Considerations - Summary Primidone is poorly tolerated in older adults avoid use if possible. Dosage adjustments are required in renal impairment. Numerous drug interactions with primidone exist. Primidone may reduce bone mineral den-sitybyinterferingwith vitamin D catabolism. Calcium and vitamin D supplementation and monitoring of bone mineral density are recommended for older adults taking this drug. 

Consult the physician to determine if he or she needs calcium and vitamin D supplements... 

Indyk and Woollard (195) demonstrated that the removal of cholesterol from the un-saponifiable fraction of vitamin D-supplemented whole milk powder by methanolic precipitation and filtration was an adequate cleanup procedure, making semipreparative HPLC unnecessary. This simplified procedure was made possible by connecting two analytical columns in series. The tandem columns adequately separated vitamins D2 and D3 from one another and from vitamins A and E. The analysis of infant formulas (100) required cleanup by silica solid-phase extraction to remove the minor tocopherols and tocotrienols, which constituted potential sources of interference. 

Aromatase inhibitors increase bone turnover by near complete estrogen depletion, leading to reduced bone mineral density and an increased risk of fractures. Bisphosphonates plus calcium and vitamin D supplementation mitigate this (26). In an open, multicenter, randomized study in 602 women with early-stage breast cancer taking letrozole 2.5 mg/day, zoledronic acid 4 mg every 6 months prevented bone loss (27). 

Problem/lnfluence of Medication. During the postoperative period, calcium and vitamin D supplements were reinstituted to facilitate bone formation. The patient, however, soon began to experience bouts of diarrhea, apparently as a side effect of the vitamin D supplements. Consequently, the vitamin D supplements were withdrawn, and only the calcium supplement was continued. Because metabolic by-products of vitamin D accelerate the absorption of calcium from the gastrointestinal tract, both agents should be administered together. This patient, however, was apparently unable... 

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