The Effect of Vitamin D Supplementation on Vitamin D Status and Parathyroid Function in Elderly Subjects*

Abstract

Vitamin D deficiency is common in the elderly and may lead to secondary hyperparathyroidism, cortical bone loss, and hip fractures. The effect of vitamin D supplementation for 1 yr was studied in 72 people living in a nursing home and 70 people living in an aged people's home. The subjects were randomized into 3 groups: control, and 400 or 800 IU vitamin D3/day. The initial vitamin D status of each subject was classified as deficient or borderline [serum 25-hydroxyvitamin D (25OHD) less than 30 nmol/L] in 79% and adequate (serum 25OHD greater than or equal to 30 nmol/L) in 21%. Serum 25OHD concentrations increased about 3-fold in both groups receiving vitamin D supplementation. Serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] concentrations increased slightly but significantly, and the increase was inversely related to the initial serum 25OHD concentration. Serum intact PTH-(1-84) concentrations decreased about 15% during supplementation in both nursing home and aged people's home residents, whereas serum osteocalcin significantly decreased in the nursing home residents only. We conclude that a vitamin D3 supplement of 400 IU/day adequately improves vitamin D status in elderly people and increases 1,25-(OH)2D concentrations in those with vitamin D deficiency. Supplementation decreases parathyroid function and may depress bone turnover to some degree.

Predictors of vitamin D deficiency and insufficiency in adult Bahrainis: a cross-sectional study

“…In addition to a marked gender difference in vitamin D levels, being significantly decreased in females compared with males, plasma PTH was also significantly higher in women than in men. The negative correlation of PTH with total 25(OH)D and the association of vitamin D deficiency with high PTH observed in the present study are consistent with a large number of reported studies (27)(28)(29) . When participants were stratified according to their vitamin D levels, Ca and PTH were decreased significantly in participants with vitamin D deficiency compared with those with insufficiency and optimal levels of vitamin D in the entire cohort and females, but not males.…”

Effect of vitamin D supplementation on vitamin D status and bone turnover markers in young adults

“…At baseline, one subject was vitamin D deficient according to the cutoff level of o25 nmol/l (Parfitt et al, 1982; Department of Health, 1998), whereas no subjects were deficient post supplementation. A level of 30 nmol/l has also been suggested as the cutoff for vitamin D deficiency (Lips et al, 1988). According to this higher level, 14.8% (n ¼ 4, all in control group) of our subjects were deficient at baseline and post supplementation.…”

“…Although a considerable number of studies have examined vitamin D status and the effect of supplementation on status in older populations (Lips et al, 1988;Liu et al, 1997;Harris et al, 2000), fewer studies have examined young people. Such studies are of particular importance among those living at higher latitudes where maintenance of sufficient vitamin D levels may be a problem given low UV exposure in wintertime (Tangpricha et al, 2002).…”

“…There is ongoing debate on the plasma 25(OH)D concentrations which are regarded as sufficient. Studies have used various biomarkers to define vitamin D sufficiency, such as changes in PTH concentrations and effects on bone metabolism (Lips et al, 1988;Bates et al, 2003). Plasma 25(OH)D concentrations of o25 (Parfitt, 1998;SACN report, 2003), 30 (Lips et al, 1988) and 50 (Lips, 2004) nmol/l have been suggested as cutoff levels for insufficiency, with the recommendation of o50 nmol/l being widely used in recent studies investigating vitamin D status.…”

Vitamin D insufficiency in older female community-dwelling acute hospital admissions and the response to supplementation

“…Such insufficiency is common in populations at risk, such as nursing home residents and the homebound elderly (Lips et al, 1987(Lips et al, , 1988Theiler et al, 1999), and it has also been described in the independent older population (Chapuy et al, 1996(Chapuy et al, , 1997bJacques et al, 1997). Thomas et al (1998) showed a high level of hypovitaminosis D in unselected medical inpatients (57%) using 37 nmol/l as a cut-off concentration.…”