Vitamin status in low versus high socio-economic groups of the North-Netherlands LifeLines population and the phenotypes of marginal/subclinical micronutrient deficiency

: Vitamins are micro-nutrients that are required for adequate functioning of many metabolic processes in the human body. Most vitamins cannot be synthesized by the human body and must therefore be ingested from food. Marginal or subclinical vitamin and micronutrient deficiencies are supposed to be very common and significantly contribute to accelerated ageing and chronic age-related diseases. Yet, current evidence is weak and intervention studies with vitamin and micronutrient supplementation often give disappointing results, possibly because single nutrients were supplemented, often in too high dosages, potentially inducing damage rather than preventing or relieving it. It is becoming more and more likely that nutrients should not be considered as single agents and that they act in a concerted metabolic network rather than in single metabolic pathways. In this way, several marginal deficiencies could act together to accelerate ageing and contribute to chronic age-related diseases.

The aims of this research project are to investigate the impact of socioeconomic status on vitamin status, markers of functional vitamin status and markers of vitamin intake, and to explore the phenotype of subclinical micronutrient deficiency in the LifeLines cohort. To this end, we measured markers of vitamin status, markers of functional status and urinary excretion of these vitamins (i.e. methylmalonic acid, vitamin B3, vitamin B6, folate, vitamin A, vitamin D, vitamin E, etc.) in elderly or pre-elderly men and women. We would like to complement these data with dp-ucMGP (a marker for functional vitamin K status) and several additional biomarkers for micronutrient intake (e.g., 24h potassium excretion as marker of potassium [fruit and vegetable] intake, 24h sodium intake as marker of sodium intake, 24h urea excretion as marker of protein intake, 24h magnesium and calcium as markers for magnesium and calcium intake). In addition, we would like to complement these data with additional measurement of creatinine, albumin and total protein in 24 h urine as markers for renal function. Unfortunately, we do not have enough sample volume (EDTA-plasma and urine) available for these additional analyses. Therefore, we would like to additionally request EDTA-plasma and 24-hour urine samples for our selection of 1605 LifeLines participants.