Optimal Serum 25-Hydroxyvitamin D Levels for Multiple Health Outcomes
Deptartment of Rheumatology, Institute of Physical Medicine, University Hospital Zurich, Zurich, Switzerland.Advances in Experimental Medicine and Biology (Impact Factor: 1.96). 02/2008; 624:55-71. DOI: 10.1007/978-0-387-77574-6_5
Recent evidence suggests that higher vitamin D intakes beyond current recommendations may be associated with better health outcomes. In this chapter, evidence is summarized from different studies that evaluate threshold levels for serum 25(OH)D levels in relation to bone mineral density (BMD), lower extremity function, dental health, risk of falls, admission to nursing home, fractures, cancer prevention and incident hypertension. For all endpoints, the most advantageous serum levels for 25(OH)D appeared to be at least 75 nmol/l (30 ng/ml) and for cancer prevention, desirable 25(OH)D levels are between 90-120 nmol/l (36-48 ng/ml). An intake of no less than 1000 IU (25 mcg) of vitamin D3 (cholecalciferol) per day for all adults may bring at least 50% of the population up to 75 nmol/l. Thus, higher doses of vitamin D are needed to bring most individuals into the desired range. While estimates suggest that 2000 IU vitamin D3 per day may successfully and safely achieve this goal, the implications of 2000 IU or higher doses for the total adult population need to be addressed in future studies.
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- "This indicates that a sufficient supply of all the vitamins A, C, D and E and perhaps vitamin B6 and K1 may be important to avoid hip fracture. Although vitamin D is an established mediator in optimizing BMD and preventing fractures, our data suggests that supplementing with vitamin D alone may be insufficient in preventing hip fracture. Low BMI is associated with increased risk of hip fracture, but our findings indicate that low levels of vitamin A, C, E and 25(OH)D are independent risk factors, and associated with hip fractures in both underweight, normal and overweight patients. "
ABSTRACT: Background: Vitamin D, and possibly vitamin K, has an established association to fracture risk. Other vitamins are, however, less studied. Aim: To determine whether specific micronutrients other than 25(OH)D and vitamin K play a role in risk of hip fracture and bone turnover. Methods: In this case-control study, blood was drawn for measurements of vitamins A, B6, B12, C, E, and folic acid as well as the bone turnover markers osteocalcin and bone-specific alkaline phosphatase upon admission for hip fracture in 116 patients and in 73 home-dwelling non fractured controls. Results for vitamin K1 and 25(OH)D from the same populations have been reported previously. Results: Low vitamin A, C, and E concentrations were independently associated with a risk of hip fracture. The adjusted odds ratio (95% confidence interval) per 10 μmol/L increase in vitamin A concentration was 0.74 (0.65-0.84); for 1 μmol/L vitamin C and E: 0.94 (0.92-0.97) and 0.81 (0.74-0.89) respectively. The results were principally unchanged when 25(OH)D, vitamin K1, Body Mass Index, and other potential confounders were adjusted for. All vitamins except B12 and folic acid correlated positively with total osteocalcin and negatively with bone-specific alkaline phosphatase. Conclusions: Low vitamin A, C, and E concentrations are associated with an increased risk of hip fracture, possibly mediated through bone turnover mechanisms. This case-control study is registered at: ClinicalTrials.gov. NCT01738776. The patient related outcome is also registered at: ClinicalTrials.gov. NCT01009268.
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- "Nevertheless, the measures here are those used in routine clinical practice in the UK. There are also some conflicting definitions of optimal vitamin D levels (Looker et al., 2002; Hypponen and Power, 2007), with some recommendations setting the threshold for vitamin D insufficiency at a level less than 75 nmol/L (Bischoff-Ferrari et al., 2006; Bischoff-Ferrari, 2008), while others that a cut off at less than 50 nmol/L defines insufficiency (World Health Organisation, 2003). Further work is needed to answer the question of causality; however , in the meantime it is important that primary and secondary health care professionals are aware of the high rates of vitamin D deficiency in psychosis. "
ABSTRACT: Vitamin D deficiency is seen in a high proportion of people with established psychotic disorders, but it is not known if this is present at onset of the illness. We set out to examine vitamin D levels in people with their first episode of psychosis (FEP). We conducted a matched case-control study to examine vitamin D levels and rates of vitamin D deficiency in sixty nine patients presenting with their FEP and sixty nine controls matched for age, sex and ethnicity. Differences between groups were tested using student's-t tests, paired t-tests and odds ratios for further analysis. Vitamin D levels were significantly lower in cases than in controls (p<0.001). The odds ratio of being vitamin D deficient was 2.99 in the FEP group relative to the control group. There was no correlation between vitamin D levels and length of hospitalisation in the patient group (r=-0.027, p=0.827). We found higher rates of vitamin D deficiency in people with FEP compared to matched controls. Given that vitamin D is neuroprotective; that developmental vitamin D deficiency may be a risk factor for psychosis, and that incipient psychosis may affect lifestyle factors and diet, future studies are required to examine this association further. In the meantime, there is a need for more widespread testing of vitamin D levels in FEP and for the development of appropriate management strategies.
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- "Potential markers of vitamin D status have been reviewed . Plasma PTH has been proposed as a functional marker, because an elevated concentration is a recognised risk factor for bone loss and fractures in older people [6-9,13,46-48], which can potentially be modified by vitamin D supplementation [49,50]. The circulating concentration of 25OHD below which PTH increases outside the normal range may be used to establish a threshold value for vitamin D insufficiency . "
ABSTRACT: The randomised, double blind intervention trial 'Optimising Vitamin D Status in Older People' (VDOP) will test the effect of three oral dosages of vitamin D given for one year on bone mineral density (BMD) and biochemical markers of vitamin D metabolism, bone turnover and safety in older people. VDOP is funded by Arthritis Research UK, supported through Newcastle University and MRC Human Nutrition Research and sponsored by the Newcastle upon Tyne Hospitals NHS Foundation Trust#. Vitamin D insufficiency is common in older people and may lead to secondary hyperparathyroidism, bone loss, impairment of muscle function and increased risk of falls and fractures. Vitamin D supplementation trials have yielded conflicting results with regard to decreasing rates of bone loss, falls and fractures and the optimal plasma concentration of 25 hydroxy vitamin D (25OHD) for skeletal health remains unclear.Method/designOlder (>=70 years) community dwelling men and women are recruited through General Practices in Northern England and 375 participants are randomised to take 12,000 international units (IU), 24,000 IU or 48,000 IU of vitamin D3 orally each month for one year starting in the winter or early spring. Hip BMD and anthropometry are measured at baseline and 12 months. Fasting blood samples are collected at baseline and three-month intervals for the measurement of plasma 25OHD, parathyroid hormone (PTH), biochemical markers of bone turnover and biochemistry to assess the dose--response and safety of supplementation. Questionnaire data include falls, fractures, quality of life, adverse events and outcomes, compliance, dietary calcium intake and sunshine exposure. This is the first integrated vitamin D supplementation trial in older men and women using a range of doses given at monthly intervals to assess BMD, plasma 25OHD, PTH and biochemical markers of bone turnover and safety, quality of life and physical performance. We aim to investigate the vitamin D supplementation and plasma 25OHD concentration required to maintain bone health and to develop a set of biochemical markers that reflects the effect of vitamin D on bone. This will aid future studies investigating the effect of vitamin D supplementation on fracture risk.ISRCTN 35648481 (assigned 16 August 2012), EudraCT 2011-004890-10.