A study that looked at brain health and Vitamin D levels was published in the journal Neurology yesterday. Over 1600 people aged 65 or older who were apparently healthy were followed for 6 years with testing for brain function. This was correlated with blood Vitamin D levels. Severe Vitamin D deficiency (less than 25 nanomoles/l) was correlated with more than 2 fold (125%) chance of acquiring a form of dementia in the study population. Moderate deficiency was associated with an increased risk of 53% of acquiring dementia. The study’s researchers concluded that a blood level of at least 50 nanomoles/l were likely to be necessary for good brain health.
It is difficult for many people in our society to get adequate levels of Vitamin D unless they are often outdoors without sunscreen, eat oily fish and fortified dairy products on a frequent basis, or take supplements. Symptoms of Vitamin D deficiency may include fatigue, fibromyalgia, weakness, and mood disorders. We already know that there are Vitamin D receptors on almost all human tissues and that it is important in the health of bones, the cardiovascular system, immunity, and the hormone system. Inadequate levels of Vitamin D have been implicated in multiple sclerosis, a disease of the nervous system. An estimated 70% of white Americans and 95% of African-Americans are vitamin D deficient. Blood tests can easily establish blood levels of Vitamin D. Supplements are readily available, and I usually recommend in the range of 1000-2000 IU of Vitamin D daily. Vitamin D comes in the form of gel caps (Trader Joes makes a good product), tablets, or drops. For most people it is a simple addition to their daily routine.
Excessive Vitamin D can cause poor appetite, nausea, vomiting, weakness, frequent urination, and kidney problems. So supplementation of more than 2000 IU/day, should be supervised by a health professional, blood levels should stay in the 50-100 nanomoles/l range with the understanding that we now have of Vitamin D function and metabolism.