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Long-awaited  vitamin D studies are finally appearing this year. A large international study found that higher levels of vitamin D in a person's blood is associated with a lower risk of colorectal cancer. Those with the highest vitamin D levels had a 21% lower risk (compared to the lowest group) of colorectal cancer after an ...continue reading "Vitamin D and Colorectal Cancer Risk"


The last post was about several reviews of vitamin D studies, and how when people are put randomly into different groups and then followed for a while - that the studies generally are not finding the same wonderful effects of higher levels of vitamin D in the blood that observational studies are finding - instead ...continue reading "Five Studies Looking at Vitamin D and Health"


The controversy over whether people should be supplementing with vitamin D or not, and whether there are health benefits or harms from vitamin D supplementation is heating up. While observational studies have found health benefits with higher vitamin D blood levels, the beneficial results have generally not held up (or mixed findings) when people were ...continue reading "Mixed Findings In Vitamin D Supplement Studies"

Vitamin D supplements are incredibly popular, but whether vitamin D supplements should be taken during pregnancy and at what dose is still debated, and studies have had conflicting results. Now a review by Canadian researchers of 43 studies of vitamin D supplementation during pregnancy found that there is "insufficient evidence to guide recommendations during pregnancy". ...continue reading "Vitamin D Supplements During Pregnancy?"

Two more studies found that higher levels of vitamin D in the blood are associated with better health outcomes - one study found a lower risk of breast cancer, especially among postmenopausal women, and in the other - better outcomes after a metastatic melanoma diagnosis. The breast cancer study suggested that a fairly high blood ...continue reading "Vitamin D, Breast Cancer, and Melanoma"

I've frequently mentioned that when taking vitamin D supplements, the one to take is vitamin D3, and not D2. Medscape (the medical site) has an article explaining that results of a recent study showed that vitamin D3 is twice as effective as D2 in raising blood levels of vitamin D. The vitamin D3 form is ...continue reading "Which Form of Vitamin D to Take?"

A recent study looking at high dose supplementation of vitamin D found that it did not prevent cardiovascular disease. This study came about because of earlier studies observing that there is a higher incidence of cardiovascular disease in persons with low vitamin D levels (as measured in their blood). But such results from observational studies ...continue reading "High Dose Vitamin D Does Not Prevent Cardiovascular Disease"

Does vitamin D prevent cancer? There has been much debate over whether increasing levels of vitamin D (as measured in a person's blood) results in a lower incidence of cancer. Studies find a number of health problems linked to low levels of vitamin D (here, here, here), while studies looking at vitamin D and cancer ...continue reading "Does Vitamin D Prevent Cancer?"

 I saw mention of this study in a number of places - that low vitamin D levels are linked to chronic headaches. A little too soon to know if that is really true -  the researchers in this study looked at the blood vitamin D levels of 2601 men just one time, and did not ...continue reading "Vitamin D and Frequent Headaches"

This study found impressive results - improvement in autistic behaviors in children diagnosed with autism spectrum disorder (ASD) with four months of daily vitamin D supplementation. Children in the placebo group did not show improvement. A nice aspect of the study was that the children were randomly assigned  to a placebo or a vitamin D ...continue reading "Vitamin D and Autism Spectrum Disorder?"