Vitamin d & parkinson's disease finnish cohort

www.pronutritionist.net

Serum Vitamin D and the Risk of Parkinson Disease

Knekt P et al.

Arch Neurol 2010; 67: 808-811.

Knekt P. et al. Arch Neurol 2010; 67: 808-811.

Background (1/2)

• Parkinson disease is a major cause of disability in elderly individuals

• Its risk factors are relatively unknown • Vitamin D plays an important role in the pathogenesis of skeletal

disorders and calcium homeostasis• Vitamin D inadequacy also predicts increased risk of other

chronic conditions as– cancer– cardiovascular diseases– type 2 diabetes

• Higher 25-hydroxyvitamin D level is also associated with lower relapse risk in multiple sclerosis

• Vitamin D deficiency might be also associated with neurodevelopmental disorders as autism and schizophrenia

Knekt P. et al. Arch Neurol 2010; 67: 808-811. www.pronutritionist.net

Background (2/2)

• Recently chronically inadequate vitamin D intake was proposed to play a significant role in the pathogenesis of Parkinson disease

– Possible mechanism might be a continuously inadequate vitamin D status leading to a chronic loss of dopaminergic neurons in the brain

• The exact mechanisms by which vitamin D may protect against Parkinson disease are not fully understood

• The epidemiological evidence of an association between vitamin D and Parkinson disease is limited to cross-sectional studies

– showing lower vitamin D status in patients with Parkinson disease compared with healthy controls

www.pronutritionist.netKnekt P. et al. Arch Neurol 2010; 67: 808-811.3

Methods

• Prospective follow-up study (The Mini-Finland Health Survey)

• Follow-up 29 years• n = 3173, aged 50 to 79 years• Serum 25-hydroxyvitamin D level was

determined from frozen samples stored at baseline

• Estimates of the relationship between serum vitamin D concentration and Parkinson disease incidence were calculated using the Cox model


Results (1/2)

• At baseline, Parkinson disease cases more often were– nonsmokers

– did not have hypertension or diabetes

than subjects who were free of the disease

• Serum vitamin D concentration was lower among Parkinson disease cases

• A significant inverse association between sex- and ageadjusted serum vitamin D level and Parkinson disease incidence was found


Results (2/2)

• Individuals with a serum vitamin D concentration

of at least 50 nmol/L had a 65% lower risk than those with values less than 25 nmol/L

• Mean serum vitamin D level in the present population was about 50% of the suggested optimal level (75-80 nmol/L)

• Despite the overall low vitamin D levels in the study population, a dose-response relationship was also found.

www.pronutritionist.netKnekt P. et al. Arch Neurol 2010; 67: 808-811.6

Discussion

• This cohort study shows that low serum vitamin D level predicts an elevated risk of Parkinson disease incidence

• Only a single measurement of serum 25 hydroxyvitamin D was available, which fails to take into account the intraindividual seasonal variation– However no interaction between serum vitamin D

concentration and season was observed

• Because of the small number of cases and the possibility of residual confounding, large cohort studies are needed

• In addition, more studies from association of vitamin D and neurological disorders is needed


Vitamin d & parkinson's disease finnish cohort

Health & Medicine

Transcript of Vitamin d & parkinson's disease finnish cohort