How Much Vitamin D is Required to be Protective Against Deficiency During the Winter Months?

The main objectives of the proposed 2 phase-protocol in aged Canadian veterans (n=60) are to evaluate the impact of 2000 IU/day of vitamin D3 supplementation (tablets or liquid form) on correcting low vitamin D status and the associated impact on biochemistry, bone health markers and markers of inflammation in a Fall period (Before and After, 8 weeks) and, 2) evaluate which food-based supplementation will maintain vitamin D3 status thereafter from winter through spring by measuring serum 25(OH)D concentration following intake of vitamin D delivered (with liquid form vitamin D3) using foods as the vehicle providing an additional 1000 IU/day or 500 IU/day compared to regular meals offered at Ste-Anne's Hospital (SAH) (Randomized Controlled Trial, 3 groups, 24 weeks). Anthropometry (weight, height, BMI, mid-arm and mid-calf circumferences), grip strength, biochemical markers of bone health (25(OH)D, PTH, calcium, ionized calcium and phosphate), assessments of cognitive and functional status (Mini-Mental State Evaluation, Frail Elderly Functional Assessment, Physiotherapy Functional Mobility Profile and Pain Assessment Checklist) as well as volumetric bone mineral density using peripheral quantitative computed tomography (pQCT) will be gathered.

The long-term goal of the research program is to use novel food-delivery systems and approaches to enhancing vitamin D intake that meets the needs of this population. For years, medications have been delivered through foods but few studies have applied this to natural health products such as vitamin D. In chronic care, the number of prescription pills is high often 13 or more not accounting for multiple administrations over a day. Further documentation of health related indicators such as capacity to perform daily activities and chronic pain intensity would relate to quality of life and improve our understanding of vitamin D in more than bone health related issues. The reality of long-term care facilities (financial, human and material resources) needs to be addressed for the newly developed delivery modes to meet the needs of these residents and the projected increase in care required for our aging Canadian population. Large scale interventions will need to take place to give more insight on efficacy and efficiency of this new food delivery approach.

Inclusion criteria

• All Veterans over the age of 70 years will be invited to participate given selection and exclusion criteria. Level 1, 2 and 3 care will comprise the recruitment pool. These levels of care permit such investigation and do not include those in palliative conditions.
• Individuals with chronic diseases will be permitted to participate as long as the disease is not end-stage (ie prognosis of more than 4 months).
• Not excluding co-morbidities or poor cognition is consistent with the work of others in the area.
• Lastly combined oral and enteral feeding modes will be included since the majority quickly transition to foods but some do take a meal-replacement/liquid supplement.

Exclusion criteria

• End-stage renal disease due to altered vitamin D metabolism and use of vitamin D analogues
• End-stage liver disease
• Untreated hyperparathyroid conditions such as cancer and metabolic bone disease except for osteoporosis and osteomalacia
• Any condition that requires enteral feeding alone as feeding route will be excluded since this oral intake, even if only partial, is a critical measurement.