Health Benefits of Sunlight and Vitamin D

Low Vitamin D Level Tied to Cognitive Decline
Study Shows Elderly People With Higher Vitamin D Levels Performed Better on Mental Tests
By Charlene Laino
WebMD Medical News Reviewed by Louise Chang, MD

April 16, 2010 (Toronto) -- Two new studies add to evidence that older people with low levels of vitamin D may be more likely to suffer from cognitive impairment.

The hope is that vitamin D supplements may be able to slow mental decline -- an intervention that one research team plans to put to the test this summer.
Vitamin D is best known for helping the body absorb calcium , which restores and strengthens bone, protecting against fracture.

But vitamin D also seems to have anti-inflammatory effects that may help keep blood vessels healthy, ensuring nutrient- and oxygen-rich blood flow to brain cells, says Amie Peterson, MD, of Oregon Health & Science University in Portland.

In addition, the presence of vitamin D receptors throughout the brain suggests that it may directly affect brain tissue, she tells WebMD.

Testing Cognitive Impairment

Still, whether vitamin D has a role in memory and cognition is unclear at this point, Peterson says, and studies have had conflicting results.

To help answer the question, Peterson and colleagues studied about 150 people aged 70 and older living on their own. Their average age was 85, and about three-fourths were women.

Participants' vitamin D levels ranged from 9 to 90 nanograms per milliliter of blood. Levels of 30 or higher are considered normal, according to Peterson.

All participants were given a standard 30-point test that is used to screen for cognitive impairment.
Results showed that the lower their score on the test, the lower their vitamin D levels.

The average vitamin D level was 42.8 for the 42 participants with a perfect score of 30 on the test; 36.7 for the 89 participants who scored between 27 and 29 ("still normal but lower," says Peterson), and 34.8 for the 21 people with scores of 22 to 26 ("mild cognitive impairment").

The study also showed that lower vitamin D levels were associated with a greater risk of falling.

This summer, Peterson and colleagues plan to embark on a study of people with Parkinson's disease to look at the effect of vitamin D supplementation on cognition, balance, and gait. Still to be tested is whether the intervention will help older people who are otherwise healthy.

Vitamin D Deficiency Common in Elderly

The second study involved 752 women, aged 75 and older, in France.

A total of 129 of the women had vitamin D levels that were below 10 nanograms per milliliter, suggesting vitamin D deficiency , which is common among older women, says Cédric Annweiler, MD, of Angers University Hospital.

Compared to women with higher vitamin D levels, those with levels below 10 were about twice as likely to have cognitive impairment, as measured by a standard test of cognitive skills, he tells WebMD.
The researchers plan to follow the women for seven years to see whether those with low vitamin D levels are more likely to develop Alzheimer's disease or other dementia , Annweiler says.

Studies like that are needed to answer the question of which comes first: vitamin D deficiency or cognitive impairment, says David Knopman, MD, a neurologist at the Mayo Clinic in Rochester, Minn., who was not involved with the new work.

"People with dementia or cognitive impairment tend to become socially isolated and less physically active, so they’re less likely to get outside" to get the benefits of the sun's vitamin-D-producing ultraviolet light, he tells WebMD.

The studies were presented at the annual meeting of the American Academy of Neurology.

 
The Health Benefits of Sunlight
Researchers have started recognizing the importance of sunlight for a healthy lifestyle, recent studies reveal that sunlight renders many health benefits. Apart from Sunlight maintaining temperature and humidity, sunlight plays a significant role in nourishing and energizing the human body. It is also vital in order to get the full nutritional value from food that you consume and it has been proven that getting sufficient sunlight aids in preventing chronic ailments such as seasonal affective disorder (SAD), osteoporosis, mental depression, type 2 diabetes, and cancers affecting the bladder, breasts, cervix, colon, ovaries, prostrate, and the stomach. To put it more succinctly, sunlight serves as the perfect medicinal pill in promoting a healthy lifestyle.
One of the prime benefits of sunlight is that it supplies the body with Vitamin D, which not only promotes the absorption of calcium in the gut but also transfers calcium across the cell membranes. This in turn provides strength to the bones as well as contributes for a healthy nervous system by increasing the production of endorphins in the brain. Usually, deposits of cholesterol-like substances known as ergosterol can be found beneath the skin, which gets converted into Vitamin D hormones when the sunlight penetrates the skin.

Vitamin D also helps to lower the level of cholesterol in blood, and sunlight can even prevent the growth of cancerous tumors. Studies show that exposing your face to sunlight for 10 minutes every day can provide your body with the Vitamin D that is required for the day. A lack of Vitamin D is associated with a host of autoimmune ailments such as Crohn’s disease, multiple sclerosis, rheumatoid arthritis, and thyroditis.

Another significant benefit of sunlight is that it helps in the prevention of infections resulting from bacteria, molds, and viruses. The health benefits of sunlight include the enhancement of the immune system by increasing the count of white blood cells as well as gamma globulin, which is beneficial in warding off viruses and germs and it enhances the capacity of red blood cells in carrying oxygen.

According to certain studies, getting adequate sunlight serves as the perfect exercise for the heart, as it enables the body to lower the resting pulse rate and decreasing hypertension, thereby making the heart healthier. Sunlight also provides resistance power to the skin, by avoiding skin diseases such as psoriasis, eczema, and acne problems. Further, getting sunlight is also correlated with the stimulation of the pineal gland, which produces such vital chemicals as tryptamines.

Other health benefits derived through the exposure of sunlight are:
• Strengthening of cardiovascular system
• Normalizing blood pressure as well as blood sugar
• Increased metabolism
• Aiding in weight loss
• Ensuring proper functioning of kidneys by eliminating wastes
• Enhanced liver function
• Improved digestion
• Above all, sunshine has that magical power to alter your moods and cheer you up, thereby preventing anxiety and depression

Despite its advantages, excess exposure to sunlight may be sometimes destructive, as it can lead to ailments such as eye damage, melanomas, and skin cancer. Likewise, over exposure to sunlight may sometimes result in a change in the color as well as the size of the skin, appearance of irregular spots on the face, and itchiness or tenderness to the skin.

In other words, benefits derived from the sunlight depend upon its usage. Methods such as sunbathing and sun tanning are considered effective for getting adequate sunshine, but make sure that you are using a quality after-sun lotion in order to moisturize your skin after sun tanning. Likewise, put on such clothes that cover your arms as well as legs after sunbathing, which in turn safeguard you from further exposure. However the most important thing to remember that an excess of anything, including sunlight, can be damaging to your health.