Effect of Vitamin D supplement use on serum concentrations of total 25OHD levels in elderly women

Resolving Vitamin D Deficiency in the Preconception Period among High-Risk Reproductive Women: A Randomized Controlled Trial

Background:

Although vitamin D deficiency has been linked to potential complications in reproductive women, the recommended intake dosage of this vitamin in populations with high incidence of deficiency in preconception period has not been defined.

Objectives:

The study investigated the effect of consuming a dosage of 2000 IU/day oral vitamin D for 105 days, on serum levels of this vitamin in reproductive women.

Materials and Methods:

229 women with 18-35 years old, who were confirmed to be vitamin D deficient (vitamin D < 75 nmol/L), were randomized into the intervention and control groups and after 15 weeks consumption of the supplement and placebo, their serum samples were obtained.

Results:

At baseline the mean serum levels of vitamin D in the control group was 23.34 ± 15.87 nmol/L and in intervention group was 25.13 ± 18.46 nmol/L, that these values didn’t have any significant difference (P = 0.43), while after intervention, significant differences between the two groups was noticed (P < 0.001). The affecting factors to achieve normal range of vitamin D in the intervention group included basal amounts of vitamin D and two underlying factors based on questionnaire data: use of oral supplements (except vitamin D and calcium) in daily life and perfect sun exposure.

Conclusion:

This study showed positive effect of the 2000 IU/day oral vitamin D on the serum level elevation of this vitamin in reproductive women.

Vitamin D status and breast cancer in Saudi Arabian women: case-control study

BACKGROUND

The role of vitamin D in breast cancer prevention is equivocal. Saudi Arabian women may be at greater risk of vitamin D deficiency because of a darker skin type and a greater likelihood of reduced ultraviolet B radiation exposure. Data regarding the vitamin D status of Saudi Arabian women and its relation to breast cancer risk are lacking.

OBJECTIVE

The purpose of this research was to evaluate the association between circulating concentrations of 25-hydroxyvitamin D [25(OH)D] and breast cancer risk in Saudi Arabian women.

DESIGN

A case-control study was conducted among 120 breast cancer cases and 120 controls. The study population was drawn from patients admitted to King Fahd Hospital in Jeddah, Saudi Arabia, from June to August 2009. Participants completed questionnaires on diet and medical history, and serum samples were collected from all women to measure circulating 25(OH)D concentrations.

RESULTS

The participants had a mean age of 47.8 y and a mean body mass index (BMI; in kg/m(2)) of 30.0. Breast cancer cases had significantly lower (mean ± SD) serum concentrations of 25(OH)D (9.4 ± 6.4 ng/mL) than did controls (15.4 ± 12.3 ng/mL; P = 0.001). In comparison with those in the highest category of vitamin D status for this population (≥20 ng/mL), the adjusted ORs (95% CIs) for invasive breast cancer were 6.1 (2.4, 15.1) for women with a serum 25(OH)D concentration <10 ng/mL and 4.0 (1.6, 10.4) for women with a serum concentration of ≥10 to <20 ng/mL (P-trend = 0.0001).

CONCLUSION

An inverse association exists between serum 25(OH)D concentrations and breast cancer risk in Saudi Arabian women. This trial was registered at clinicaltrials.gov as NCT01817231.

An age-related decrease in creatinine clearance is associated with an increase in number of falls in untreated women but not in women receiving calcitriol treatment

CONTEXT

Decreased calcitriol production due to impaired renal function may be a significant risk factor for falls in normal aging population.

OBJECTIVE

The objective of the study was to examine the association between creatinine clearance (CrCl) and the incidence of falls and fallers in groups treated with placebo, calcitriol, estrogen therapy (ET)/estrogen + progestin therapy (HT), and calcitriol + ET/HT.

DESIGN

This was a 3-yr, double-blind, placebo-controlled study designed to test the efficacy of calcitriol and ET/HT on bone loss and falls with analysis by intention to treat and post hoc.

SETTING

The study was conducted at an academic outpatient center.

PARTICIPANTS

Four hundred eighty-nine normal elderly women aged 65-77 yr; 415 women completed the study.

INTERVENTION

Subjects were randomized to placebo, calcitriol 0.25 mug twice a day, ET daily (conjugated equine estrogens 0.625 mg), HT (conjugated equine estrogen 0.625 mg + medroxyprogesterone acetate 2.5 mg) and calcitriol + ET/HT.

MAIN OUTCOME MEASURES

Cumulative number of falls and fallers were compared between groups with 24-h urine CrCl less than 60 and 60 ml/min or greater.

RESULTS

Calcitriol treatment decreased the number of fallers and falls. Low CrCl less than 60 ml/min was a predictor of the number of falls per person but not fallers in the placebo group (P = 0.007). In the low CrCl group (<60 ml/min), the rate of falls decreased on calcitriol by 53% [95% confidence interval (CI) -71% to -22%; P = 0.003], calcitriol + ET/HT by 61% (95% CI -76% to -37%; P = 0.001), and ET/HT by 25% (95% CI: -55% to +24%; not significant). Calcitriol reduced the rate of falls by 30% (95% CI -49% to -4%; P = 0.027) in the CrCl 60 ml/min or greater group.

CONCLUSION

Calcitriol treatment decreases falls in all subjects but especially in elderly women with decreased renal function (<60 ml/min) and frequent fallers.

The vitamin D questions: How much do you need and how should you get it?

UV radiation is a well-documented human carcinogen, indisputably linked to the current continued increased rate of skin cancer. UV radiation is also responsible for cutaneous synthesis of vitamin (vit) D3, a substance that is then sequentially hydroxylated in the liver and kidney to yield 1,25(OH)2 vit D, a hormone critical for calcium homeostasis and skeletal maintenance. Because the UV action spectra for DNA damage leading to skin cancer and for vit D photosynthesis are virtually identical, the harmful and beneficial effects of UV irradiation are inseparable. This has given rise to the argument that sun avoidance, with a goal of skin cancer prevention, may compromise vit D sufficiency. Public interest in this matter has been heightened in recent years by multiple studies correlating the level of 25-OH vit D, the readily measurable "storage" precursor form of the vit, with a variety of benefits separate from skeletal health. Although the studies are of variable quality and all alleged treatment benefits are based on dietary supplementation with vit D, not on increased sun exposure, they have been interpreted by some as support for advocating increased sun exposure of the public at large. The goal of this review is to provide a detailed, balanced, and referenced discussion of the complex literature underlying the current popular interest in vit D and sun exposure for the purpose of increasing vit D photosynthesis. We review the nomenclature, metabolism, and established functions of vit D; the evidence supporting the less well-established but purported vit D effects; the concept of vit D insufficiency; populations at risk for vit D deficiency; and finally the risk/benefit of obtaining vit D from cutaneous photosynthesis versus diet or supplementation.