Vitamin D

Vitamin D

How much Sun do I need?

Sun Exposure Times Required to Make Vitamin D at 50-75% skin exposure (t-shirt shorts or swimsuit without sunscreen. 3 x per week to make adequate Vitamin D

Check the UV index of the day at weather.com

What type of skin do you have? 1 = always burn never tan 2 = burn easily, rarely tan

3 = occasionally burn, slowly tan 4 = rarely burn, rapidly tan 5/6 = never burn, always dark

Skin Type	UVI 0-2	UVI 3-5	UVI 6-7	UVI 8-10	UVI 11+
Type 1	No D made	10-15	5-10	2-8	1-5
Type 2	No D made	15-20	10-15	5-10	2-8
Type 3	No D made	20-30	15-20	10-15	5-10
Type 4	No D made	30-40	20-30	15-20	10-15
Type 5-6	No D made	40-60	30-40	20-30	15-20

Most tanning beds are around UVI 7-8 Double exposure time if over age 50

You will not overdose on vitamin D from the sun. Your body will simply stop producing vitamin D if you have enough. As you tan it takes longer to make vitamin D. The side effects of too much sun are sun burn, skin damage and potentially skin cancer.

What is my Risk of Low Vitamin D (Take the Quiz)

You have skin type 4,5,6 (3 points)

BMI is 30 or greater (weight in lbs x 703 divide by height in inches squared) (3 points)

You are a breast fed infant not on vitamin D or formula (3 points)

You have fatigue or recurring muscle, bone, or joint pain (2 points)

You are over 50 (2 points)

You live north of Texas (2 points)

You wear sunscreen of SPF 8 or greater or hat and shirt before you go outside (2 points)

You spend less then 3 days a week outside between 11-4 pm with your shirt off. (2 points)

Below 2 = low risk 3-5 = high risk over 5 = very high risk

Vitamin D Supplements?

Step 1 Figure out what your current Vitamin D level is. Ask your doctor for a blood test.

The desired level is between 50-70. Follow the chart to figure out how much Vitamin D you should be supplementing. Recheck your blood level in 1- 3 months.

Amount of Vitamin D in IU/ Lb. per day Needed

Desired	70	46	42	38	34	30	26	23	19	nc	-8	-11	-15
Vitamin D	60	38	34	30	26	23	19	15	11	nc	-15	-19	-23
Level	50	30	26	23	19	15	11	8	4	nc	-23	-26	-30
	40	23	19	15	11	8	4	nc	nc	nc	-30	-34	-38
Measured Vitamin D Level		10	15	20	25	30	35	40	45	50-70	80	85	90

If you are not planning on getting your blood tested you can assume 20-25 IU /LB per day should be enough to produce vitamin D in the normal range.

What does vitamin D do for the body?

This essential nutrient is called a vitamin, but dietary vitamin D is actually a precursor hormone — the building block of a powerful steroid hormone in your body called calcitriol. It’s been known for many years that vitamin D is critical to the health of our bones and teeth, but deeper insight into D’s wider role in our health is quite new.

Major vitamin D functions

• Supports key mineral absorption and metabolism (especially calcium and phosphorus in the blood and bones).
• Regulates normal cell differentiation and proliferation (e.g., prevention of cancer).
• Promotes insulin sensitivity and blood sugar regulation (insulin secretion).
• Regulates over 200 genes through binding to vitamin D receptors throughout the body.

Obesity – People who have reduced vitamin D often weigh more and have more body fat than those with adequate vitamin D levels. In the past 20 years multiple studies have shown a correlation between higher blood levels of vitamin D and leaner body mass. Low vitamin D levels lead to more energy being stored as fat. Muscle mass decreases and lowered metabolism which leads to weight gain. In wild animals as day light decreases in the fall, hormones like cortisol are elevated. This hormone helps animals fatten up for the long winter ahead. Cortisol causes us to burn sugar and store fat. As we burn sugar we crave sugar. Tests animals who ate the same diets gained more weight if Vitamin D was low. Low vitamin D also leads to fatigue and depression which lead to inactivity and weigh gain.

Diabetes and Metabolic Syndrome - Many of the 23 million Americans with diabetes have low vitamin D levels. Evidence published on pubmed.gov suggests that vitamin D plays an integral role in insulin secretion, synthesis and sensitivity (Diabetologia. 2005 Jul;48(7):1247-57. Epub 2005 Jun 22). Vitamin D helps regulate blood calcium levels, which regulate insulin synthesis and secretion, and it has a direct action on pancreatic beta-cell function, which produce insulin. Vitamin D is necessary in the cells to allow the insulin receptors to attach insulin. A recent review article published by researchers from Loyola University Chicago Marcella Niehoff School of Nursing concluded that adequate intake of vitamin D may prevent or delay the onset of diabetes and reduce complications for those who have already been diagnosed. These findings appeared in the latest issue of Diabetes Educator. Vitamin D deficiency has been associated with autoimmune disease including Type 1 diabetes.

Heart Disease and High Blood Pressure - Researchers say a growing body of evidence suggests that vitamin D deficiency increases the risk of heart disease. Several large studies have shown that people with low vitamin D levels were twice as likely to have a heart attack, stroke, or other heart-related event. Low vitamin D causes stress hormone renin and angiotensin to be elevated. Vitamin D inhibits the gene that makes renin. These hormones constrict blood vessel and raise blood pressure. Increased blood pressure makes the heart have to pump harder causing it to wear out faster. Low vitamin D leads to inflammation that damages blood vessels leading to atherosclerosis and higher cholesterol. Vitamin D reduces the stickiness of the blood vessels and reduces inflammation caused by white blood cells.

Improved Brain Function, Better Mood and Memory – In a study done in Norway and recently published in the Journal of Internal Medicine, researchers found a relation between blood levels of vitamin D and symptoms of depression. Seasonal affective disorder, or SAD, is a mood disorder brought on by decreasing daylight in the winter months. High doses of vitamin D during these months have proven to be a very effective natural remedy for SAD. Vitamin D levels are inversely related to those of melatonin, another mood-regulating hormone. Melatonin helps modulate your circadian rhythms, with darkness triggering melatonin secretion by the pineal gland within your brain, bringing you down gently at night for sleep. Insomnia, mood swings and food cravings are influenced by melatonin. Sunlight shuts melatonin production off, while triggering release of vitamin D — that’s why doctors recommend getting outdoors as a remedy for jet lag. Most of us can sense the positive influence of sunlight in our own lives by the immediate lift we get from taking a walk outdoors on a beautiful sunny day. Now there may be many factors at work that brighten our mood in such cases, but sun exposure is almost certainly a critical piece.

The findings from the researchers at the Peninsula Medical School, the University of Cambridge and the University of Michigan revealed that compared to those with optimum levels of vitamin D, those with the lowest levels were four times more likely to be cognitively impaired.

Vitamin D is thought to influence cognitive function in a positive way by increasing a brain chemical called acetylcholine which influences memory.  Vitamin D also stimulates synthesis of nerve growth factor.  Vitamin D has been shown to protect against stroke and by its ability to stop nerve damage could have a major impact in preventing neurodegenerative diseases like Alzheimer’s and dementia.

Optimize Immune System - The study, the largest to date on the link between vitamin D and common respiratory infections, shows that people with the lowest vitamin D levels report having significantly more cases of cold and flu than those with higher levels. Typically we see a spike in infections and illnesses as we are exposed to smaller amounts of sun in the winter. The results of several studies showed those with the lowest vitamin D levels (less than 10 nanograms per milliliter of blood) were 36% more likely to report having a recent upper respiratory tract infection than those with higher levels (30 ng/mL or higher).

Prevent and Treat Cancer - Evidence is mounting that vitamin D may protect against some cancers, particularly breast cancer, prostate cancer, and colorectal cancers. In fact, over 60 years of research have shown vitamin D supplementation or sunlight-induced vitamin D conversion to be associated with lower incidence of cancers. Many of these cancers kill more people in northern climates and affect those with skin pigmentation at a higher rate. Vitamin D deficiency most certainly affects your immune system because calcitriol actually helps regulate cell division, so adequate levels may help sustain normal cell growth.

Vitamin D has been found to cause regression of brain tumors like glioblastoma and astrocytoma in some suffering from these forms of cancers.

PMS and Hormone Regulation - A recent study by scientists at the University of Massachusetts found that a diet rich in calcium and vitamin D can help control some symptoms of PMS, such as tearfulness, anxiety, and irritability.

Healthier Bones, Joints, and Teeth - Low vitamin D leads to the release of stress hormones that lower grow hormone needed to make strong bones and muscles. As we age, our bodies slowly lose the ability to mobilize vitamin D, a process that lowers our calcium absorption rates. This creates a higher risk of osteoporosis, particularly in post-menopausal women.

Autoimmune Disease - Low vitamin D has been shown to be associated autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, insulin-dependent diabetes mellitus, and inflammatory bowel disease. One study looked at the vitamin D intake in more than 187,000 women from two separate groups followed for 10 and 20 years. Overall, the risk of MS was 40% lower in women with the highest vitamin D levels. All were supplementing with vitamin D. Vitamin D from food had no effect on the incidence of MS in this study. A second study showed that vitamin D intake decreased the risk of developing RA in a population of 29,000 women. A third study showed Vitamin D supplementation significantly reduced the development of insulin dependent diabetes during infancy in 10,366 children. Vitamin D deficiency is common in patients with Crohn’s disease even when the disease is in remission.

Vitamin D regulates the differentiation and activity of CD4+T cells to suppress autoimmune disease pathology. The hypothesis is that vitamin D blocks Th1 and improves regulatory T cells and Th2 cells. In the absence of adequate vitamin D, the immune system favors the development of self-reactive T cells and autoimmunity.

Margherita T. Cantorna¹ and Brett D. Mahon Mounting Evidence for Vitamin D as an Environmental Factor Affecting Autoimmune Disease Prevalence Experimental Biology and Medicine 229:1136-1142 (2004)
© 2004 Society for Experimental Biology and Medicine http://www.ebmonline.org/cgi/content/full/229/11/1136#SEC3