IMPaCT associated studies
Vitamin D deficiency in people with severe mental illness
Vitamin D deficiency has been linked to a number of physical health problems including cardiovascular disease, diabetes, bone fragility, musculoskeletal pains, autoimmune diseases, infectious diseases and cancer (Holick, 2008; Sivenpiper, 2008). The main causes for vitamin D deficiency are not enough exposure of the skin to ultraviolet light and not enough dietary vitamin D (Pasco et al., 2001). Secondary causes include disorders that affect the absorption and metabolism of vitamin D, and also prescribed anticonvulsant medication.
Psychiatric patients, especially those who are institutionalised, are likely to be subject to the main causes of vitamin D deficiency; but they are also more likely to be prescribed anticonvulsant medication, which is known to deplete vitamin D. This link between psychiatric illness and vitamin D deficiency is well-documented. For example, Schneider et al. (2000) compared a group of patients with various psychiatric illnesses (schizophrenia, depression, alcohol dependence) to a group of healthy controls, and found that those with schizophrenia had consistently lower levels of vitamin D. Tiangga et al. (2008) studied chronically ill male psychiatric inpatients with no specified diagnosis and found that 15 out of 17 of them had severe vitamin D deficiency. Other studies have reported similar findings but they do not show that this deficiency is unique to schizophrenia or other psychotic disorders.
Our secondary aims
We also hope to find out:
- If vitamin D levels in people with severe mental illness correlate with physical activity scores
- If vitamin D levels increase in people with severe mental illness who receive the health promotion intervention
- If the health promotion intervention has a greater or lesser effect in ethnic minority populations
- The extent to which co-morbidities (such as depression and diabetes) exist in people with severe mental illness who have low vitamin D levels (hypovitaminosis D)
- If antipsychotic or other drugs that are linked to a sensitivity to light (photosensitivity), such as clozapine and chlorpromazine, are associated with higher levels of vitamin D
- If vitamin D levels are low in people with chronic psychosis compared to first onset psychosis; and if so, whether vitamin D levels are lower in people with chronic psychosis compared to those with first onset psychosis
- If there is any link between low vitamin D levels in people with chronic psychosis and the presence of depressive/negative symptoms
What is needed is a more practical and integrated solution, which is tailored to each individual and focuses on both lifestyle choices and substance use in order to maximise both physical and mental health.