Vitamin D is a hormone produced in the skin via a non-enzymatic process involving ultraviolet light.It is well known that the physiology of aging makes older people particularly susceptible to... Show moreVitamin D is a hormone produced in the skin via a non-enzymatic process involving ultraviolet light.It is well known that the physiology of aging makes older people particularly susceptible to vitamin D deficiency and that, if untreated, it can have serious health consequences. This thesis deliberates on the topics of vitamin D supplementation in older people in light of the current guidelines and on the possible additional effects of ultraviolet light beyond vitamin D synthesis on nursing home residents. We present a cross-sectional study in nursing home residents aged 70 years and over designed to evaluate the efficacy of vitamin D supplementation in achieving vitamin D sufficiency. We also discuss the different supplementation strategies for nursing home residents and community dwelling persons aged 70 years and over based on a survey administered to general practitioners and elderly care physicians in the Netherlands.In the second part we concentrate on additional effects of ultraviolet light beyond vitamin D synthesis. We describe our systematic review of literature on the effect of ultraviolet light, when applied to the skin or eyes, on mood, depression and well-being. We present also our randomized controlled trial on the effect of ultraviolet radiation compared with oral vitamin D supplementation on the well-being of nursing home residents with dementia. Further we use the data of the RCT to carry out a post-hoc analysis to compare the effect of vitamin D alone compared with ultraviolet radiation on the blood pressure of old people with dementia. Show less
This PhD project revealed that the female hormonal status – including OC use – and stress vulnerability – as defined by the MR-haplotype – have practical implications in experimental psychological... Show moreThis PhD project revealed that the female hormonal status – including OC use – and stress vulnerability – as defined by the MR-haplotype – have practical implications in experimental psychological research. Furthermore, incorporation of these variables in models of emotional information processing may be of help in understanding and treating mood disorders in women. Namely, even small biases may affect information processing and may contribute to the resilience or proneness to mood-disorders.Our research was among the first to show that the genetic makeup of healthy women may play a role in the influence of the female hormonal status on emotional information processing. Healthy female MR-haplotype 1/3 carriers may be more prone to distress, and may also be more sensitive to (pharmacological) changes which may counteract or sustain their vulnerability. Consistently, we observed subtle markers of depressogenic side-effects of OC only in MR-haplotype 1/3 carriers. Our findings regarding the MR-haplotypes 2 carriers are generally in line with earlier observations. We observed that MR-haplotype 2 carriers – especially homozygotes – are the less susceptible, more optimistic and more rational individuals, also in ‘unstressed’ conditions. However, stress-related psychopathology is very heterogeneous by nature and proteins from multiple genes are likely to interact in the stress-susceptibility phenotype. Last but not least, we should not ignore that the increased vulnerability of women to mood disorders is the result of a plethora of biological, psychological and sociological factors.OC-users had lower affect variability and reduced sensitivity to interpersonal emotional cues. This may be experienced as either a stabilizing or a blunting effect of OC, perhaps depending on the individual’s appraisal. The lower depression scores of OC-users in our longitudinal study suggests a protective effect of monophasic OC on symptoms of reproductive depression. Future studies should investigate (former) OC-users in larger cohorts including novel users, satisfied users and ‘brand-switchers’ in order to control for the survivor effect. Show less