Dr. Garland and the Benefits of Vitamin D

Frank C. Garland passed away recently. He and his brother Cedric published one of the first papers leading to our new understanding of the importance of vitamin D. They found that cancer mortality rates were highest in places where populations were exposed to the least amounts of natural light including major cities and rural areas at high latitudes. That was just the beginning!

see Frank C. Garland, 60, Who Connected Vitamin D Deficiency and Cancer, Dies

We've known for a long time that vitamin D helps maintain normal blood levels of calcium and phosphorus and that vitamin D aids the absorption of calcium to give us strong bones. We've also known that vitamin D deficiency in children causes rickets leading to skeletal deformities and that vitamin D deficiency in adults causes osteomalacia leading to muscular weakness and fragile bones. That was roughly all we knew.

We get most of our vitamin D through exposure to sunlight. We absorb the sun’s ultraviolet-B rays through our skin where we convert it to Previtamin D. 10% - 15% of Previtamin D is converted to Vitamin D3. Then, our liver converts Vitamin D3 to 25-hydroxyvitamin D which is the primary form of Vitamin D circulating in our bloodstream. Finally, our kidneys and monocyte-macrophages (immune cells) convert 25-hydroxyvitamin D into its biologically active form; 
1,25-dihydroxyvitamin D (also known as vitamin D hormone). We have four organs dedicated to producing vitamin D; our skin, liver, kidneys, and immune system. Evolving such an elaborate cascading system for producing various forms of Vitamin D implies its importance!

see Vitamin D

What's new?

Following the Garlands' research, scientists went on to unearth a tome of new information on how this vitamin helps us. They discovered that vitamin D works on a genetic level supporting the regulation of thousands of genes. It may be a co-factor in nearly 200 important metabolic processes. It appears to regulate blood pressure and glucose levels. It regulates and boosts
 the immune system. It may also protect nerve cells, promote protective hormonal activity in the brain, and increase levels of antioxidants in the brain that reduce the buildup of toxic chemicals known as free radicals. Amazing!

Cancer and Autoimmune Disease

Many of the genes that vitamin D helps regulate are associated with autoimmune disease and cancer. Such autoimmune diseases include type 1 diabetes, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus. In addition to colon cancer, vitamin D deficiency is linked with breast and prostrate cancer.

see Vitamin D affects autoimmune diseases and cancer genes
see Do sunlight and vitamin D reduce the likelihood of colon cancer?

Heart Disease

Scientists are also learning that vitamin D may help the heart by regulating blood pressure, inflammation and glucose control. A study looking at patients' vitamin D levels found those with the lowest vitamin D levels were 77% more likely to die of heart failure after surviving a first heart attack, 78% more likely to have a stroke, and 45% more likely to develop coronary artery disease than those with normal levels of vitamin D.

see Vitamin D Shows Heart Benefits in Study

Parkinson's Disease and Dementia

Vitamin D may also help memory and information processing. 
Research published in January 2009 suggested high levels of vitamin D may help stave off mental decline associated with aging. Another study tracking individuals for over 30 years found individuals with low levels of vitamin D may be three times more likely to develop Parkinson's disease than individuals with normal levels. Vitamin D may help us mentally by protecting nerve cells, promoting protective hormonal activity in the brain, and increasing levels of antioxidants in the brain that reduce the buildup of toxic chemicals known as free radicals.

see Low vitamin D levels 'linked to Parkinson's disease'
see Vitamin D 'key to healthy brain'

Cold and Flu

In yet another recent study, people deficient in vitamin D were 36 % more likely to get respiratory infections than those with sufficient levels; people with chronic obstructive pulmonary disease (COPD) and vitamin D deficiency were 200% more likely to get respiratory infections than their non-deficient counterparts; and, asthmatics with vitamin D 
deficiency were 500% more likely to get respiratory infections than their non-deficient counterparts. Vitamin D is associated with the production of an antimicrobial peptide that works with the immune-system to kill pathogens. People deficient in vitamin D make less of this peptide.

Vitamin D deficiency linked to more colds and flu

Athletic Performance

There is strong evidence that getting adequate amounts of vitamin D may improve athletic performance. This is helpful to know because more athletes are deficient than you would expect. One study found several long distance runners to have low vitamin D levels.

see Can Vitamin D Improve Your Athletic Performance?

Current Recommendations

Recent studies on Vitamin D give hope for a simple and inexpensive solution to many serious health problems. However, scientists still need to perform more studies to clarify their initial correlations. In addition, researchers don't yet know what level is optimal or at what point vitamin D becomes toxic. Symptoms of vitamin D toxicity include nausea, vomiting, poor appetite, constipation, weakness and weight loss, as well as dangerously increased calcium levels that can result in kidney stones, confusion and abnormal heart rhythms.

The best way to get vitamin D is through exposure to sunlight. After that, you can obtain vitamin D from fortified milk, cheese, fish oil, eggs, and meat. However, it's unlikely you'll get enough from diet alone. Those at risk for vitamin D deficiency not only include those with limited exposure to sunlight. The elderly, obese, and exclusively breastfed infants also may be deficient. In addition, those with malabsorption syndromes (e.g., cystic fibrosis) or inflammatory bowel disease (e.g., Crohn's disease) are at risk.

The Institute of Medicine has historically recommended dosages of 200 I.U. a day to age 50 (including pregnant women); 400 I.U. for adults 50-70; and 600 I.U. for those older than 70. However, the Institute of Medicine currently considers these recommendations low and are deciding how much to ramp them up. Currently, doctors recommend between 1,000 to 2,000 I.U. for those who don't get enough sunlight, pregnant and lactating women, and adults older than 50. The American Academy of Pediatrics recommends giving breast-fed infants 400 I.U. of vitamin D per day until they are weaned and consuming a quart or more of fortified milk or formula a day.

see What Do You Lack? Probably Vitamin D
see Vitamin D - Mayo Clinic

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