Vitamin D Has More Benefits Than Previously Thought

May 17, 2019 · Posted in Potential Treatments · Comment 

supplementsVitamin D has long been known as an important vitamin for bone health, preventing conditions such as osteoporosis and rickets. More recently, research suggests that vitamin D may also protect against conditions such as cancer, heart failure, diabetes, respiratory tract infections, and autoimmune disease.

Many Americans have low vitamin D or a vitamin D deficiency. The human body produces vitamin D in large amounts when the skin is exposed to ultraviolet B rays in sunlight. Vitamin D can also be absorbed from vitamin D–fortified foods such as dairy products, some orange juice, and cereals. Some foods such as fatty fish, beef liver, and egg yolks naturally contain some vitamin D, but it is difficult to get enough vitamin D just from consuming these foods.

Low mood or seasonal affective disorder (SAD), in which people feel depressed during winter periods of limited exposure to sunshine, have been linked to low vitamin D.

Other symptoms of low vitamin D vary but can include pain in the joints, bones, or muscles; fatigue; and breathing problems.

Editor’s Note: A few small studies have suggested that 1,500 IU per day of vitamin D supplements can help depressed mood, even in those with normal vitamin D levels. Several studies have indicated that children or adolescents with psychiatric disorders are especially likely to be vitamin D–deficient. Another study found that higher amounts of vitamin D (4,000 IU) could improve cognition in healthy volunteers more than lower doses could. Vitamin D also improved cognition in people with multiple sclerosis and in those with the autoimmune disease Hashimoto’s thyroiditis.

Vitamin D Deficiency in Newborns Linked to Higher Risk of Schizophrenia in Adulthood

May 13, 2019 · Posted in Risk Factors · Comment 

mother and babyA 2018 study by Darryl W. Eyles in the journal Scientific Reports found that newborns with vitamin D deficiency were more likely to develop schizophrenia later in life. The study made use of several Danish data depositories and had a large sample size of 2,602 participants. In this case control study, registries of patients treated for schizophrenia were matched up to preserved dried blood samples collected at their births, and these were compared to other dried blood samples from people without schizophrenia who shared the same sex and birthdate.

The researchers divided participants into quintiles based on vitamin D levels at birth. Compared to those who fell into the fourth quintile, those in the lowest quintile were 44% more likely to be diagnosed with schizophrenia in adulthood. The researchers also determined polygenic risk scores for each participant, that is, they calculated schizophrenia risk based on the presence of various genes. The two processes together explained 1.2% of the variance in schizophrenia diagnoses.

Risk factors for vitamin D deficiency include being born in the winter or spring, living in high-latitude locations, spending early life in an urban setting, and being darker-skinned (especially in high-latitude locations). These risk factors are all correlated with decreased skin absorption of UV rays from the sun, which is how the human body produces vitamin D. The vitamin D receptor is expressed in the brain in areas that are relevant to schizophrenia, such as areas with a lot of dopamine activity, and each of the above risk factors also applies to schizophrenia.

As expected, participants born in the winter and spring had lower vitamin D levels. Participants whose parents had immigrated to Denmark had lower vitamin D than those with parents native to Denmark.

Newborns’ vitamin D levels depend completely on their mothers’ vitamin D levels, so Eyles and colleagues suggest that ensuring pregnant women have adequate vitamin D levels could prevent some cases of schizophrenia.

Adolescents with Bipolar Disorder May Have Higher Levels of Vitamin D–Binding Protein

May 7, 2019 · Posted in Diagnosis, Risk Factors · Comment 
illustration of vitamin D binding protein

Vitamin D binding protein. Illustration: Emw [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]

A 2018 article by Brawnie Petrov and colleagues in the journal Translational Psychiatry suggests that adolescents with bipolar disorder have higher levels of vitamin D–binding protein than adolescents without a mood disorder. The researchers wrote that vitamin D–binding protein “responds early to cellular damage by binding…structural proteins and activating inflammatory cells.”

This pilot study suggests that measuring levels of vitamin D–binding protein could be a useful marker of bipolar disorder. The study was small, with only 12 participants who had bipolar disorder, 11 who had unipolar depression, and 13 with no mood disorder. The researchers hope to follow up with larger studies in adolescents and adults using blood that has already been collected from people with bipolar disorder.

Vitamin D–binding protein is not measured by a standard blood test. The study authors used a technique where they “fished” for inflammatory factors that might be linked to mood disorders. The researchers began by looking for a link between other inflammatory markers in the blood and bipolar disorder, which have repeatedly been found in other studies, but they did not find any such association. There also did not seem to be a link between bipolar illness and vitamin D levels in the blood, only vitamin D–binding protein levels.

It can be especially difficult to distinguish early bipolar disorder from unipolar depression, and if the results of this small study are replicated, a blood test might eventually help to identify people with bipolar disorder earlier.

Meta-Analysis Finds Omega-3 Fatty Acids Do Not Reduce Cardiovascular Disease Risk

May 1, 2019 · Posted in Potential Treatments · Comment 

heartIn a 2018 meta-analysis published in the journal JAMA Cardiology, researcher Theingi Aung and colleagues found that across 10 studies including a total of 77,197 participants, omega-3 fatty acid supplementation did not reduce risk of coronary heart disease in people at high risk. This newer finding conflicts with a 2017 advisory from the American Heart Association that suggested omega-3 fatty acid supplementation might prevent cardiovascular disease.

When it comes to mood disorders, it has been similarly difficult to pin down whether omega-3 fatty acids are helpful. Data on omega-3 fatty acid supplements for the prevention of depression have been ambiguous, with small numbers of studies and variations in study design that make it difficult to draw strong conclusions about whether these supplements can improve or prevent depression.

A 2016 systematic review by Paola Bozzatello and colleagues in the Journal of Clinical Psychiatry found only seven studies of omega-3 fatty acid supplementation in bipolar disorder. The studies had small sample sizes and widely varying dosage parameters, so the evidence that can be drawn from them is not strong, but the review did find a modest benefit on bipolar depression (but not mania) when omega-3 fatty acids were added to a treatment regimen, compared to treatment as usual.

The same review found that studies of omega-3 fatty acid supplementation in unipolar depression also varied widely, and thus it was difficult to draw inferences from them. Some meta-analyses found no benefit to omega-3 fatty acid supplementation, while others suggested that omega-3s could improve depression. The review found that the type of omega-3 fatty acids used might matter. Supplementation with EPA seemed to improve depression more than supplementation with DHA. The review also cited a 2014 comprehensive meta-analysis by Giuseppe Grosso and colleagues in the journal PLoS One that analyzed the findings from 19 studies in people with depression or depressive symptoms. Grosso and colleagues found that people with more severe depression seemed to benefit more from omega-3s.