Info from naturalhealthcarenorthwest.com
Vitamin D: New Evidence for This Vitamin’s Importance in Health
Vitamin D was discovered in the 1900’s, during the industrial revolution when Rickets, a condition causing weakened bones and bowed legs in children, was found to be due to a deficiency of vitamin D. In fact, “vitamin” D is both a vitamin and a hormone, there are two ways that humans obtain it. The first way is through exposure of the skin to ultraviolet light (sunshine), which allows the skin to produce vitamin D3 , also called cholecalciferol. Cholecalciferol is then converted by the liver and then by the kidneys to the active form of the vitamin D, which has the health promoting and hormonal benefits. Many factors can inhibit production of vitamin D from sunlight exposure including living in higher latitudes where less sunlight reaches the Earth’s surface, especially in the winter months. Of course, as concerns for skin cancer have risen so has the usage of sunscreen. 10,000-25,000 IU of Vitamin D can be produced daily with full body exposure to sunlight. However almost all of the UVB rays are blocked by SPF 8 or higher sunscreen, and this prevents adequate production of Vitamin D on the skin.
Dr. Jonathan Wright, MD suggests that patients should get a bit of sunscreen-free sunlight exposure daily, stopping when a slight pinkness is noted on the skin. I agree with this advice in general, but obviously, sun-exposure may be ill-advised for patients with previous skin cancers, and is not possible in certain climates or at certain times of the year. Seattle is a city that clearly presents disadvantages to its residents for vitamin D production during our cloudy, shorter winter days!
The second way to obtain vitamin D is orally, through diet or supplementation. Unfortunately, vitamin D is rather difficult to obtain from foods. Dairy and cod liver oil are two good sources, but even these foods would have to be consumed in very large amounts in order to get adequate vitamin D orally.
Many patients and doctors have been trained to fear vitamin D as potentially toxic. The Food and Nutrition Board previously defined the Upper Limit for safe intake of vitamin D at 2,000 IU per day. While it is true that vitamin D has potential for overdose, researchers are now presenting evidence that it is actually required and safe at dosages of 4,000-5,000 IU per day for adults. Dosage of 100,000 IU daily for several months in adults and 40,000 IU daily in infants for 1-4 months are likely to be toxicity inducing. You may be susceptible to toxicity at lower dosages if you have excess blood calcium levels, hyperparathyroidism, hyperthyroidism, granulomatous diseases such as sarcoidosis, Crohn’s disease and tuberculosis, certain cancers, or if you are taking certain drugs that make you more sensitive to vitamin D. The symptoms of vitamin D toxicity are loss of appetite, nausea or vomiting, feeling nervous or weak, itching, excessive thirst, increased urination, and elevated blood calcium levels. However, if you are supplementing with vitamin D, you probably can avoid toxicity by having your doctor regularly monitor your blood calcium and vitamin D levels. The best blood test for vitamin D is called serum 25-OH-vitamin D. This can be done on a weekly to monthly basis depending on your individual health and on the dosage of vitamin D that you are taking.
The many health benefits and preventive health advantages of vitamin D supplementation outweighs the potential for toxicity. Also, there is ample evidence that vitamin D deficiency is more widespread than was previously thought. Let’s take a look at some of the research:
Hypertension and Heart Disease
High blood pressure and heart attacks are more common in winter months and in locations farther away from the equator (conditions where sunlight is less ample). People with higher blood levels of vitamin D had naturally lower blood pressures. Vitamin D is known to lower a blood pressure raising substance in the body called angiotensin II. If your blood 25-OH-vitamin D levels is lower than 34 ng/ml your risk of heart attack is doubled, compared to people whose levels are above 34.
Low sunlight exposure and low vitamin D status is associated with increase risk of dying of numerous cancers including breast, ovarian, uterine, prostate, stomach, bladder, and lung cancers and non-Hodgkin’s lymphoma. The researcher who made this connection suggested that 23,000 American lives could be saved yearly by adequate sunlight exposure and/or vitamin D supplementation.
Studies showed knee and hip arthritis worsened faster in patients with 25-OH-vitamin D levels below 30 ng/ml.
Studies showed vitamin D supplementation is equally or more successful in treating Seasonal Affective Disorder compared with use of a lightbox.
Pain: Migraines and Musculoskeletal pain
Women with migraines who test as deficient in vitamin D often have improvement in their migraines if they begin taking vitamin D and calcium daily.
Several studies showed that patients with persistent muscloskeletal pain and low back pain had vitamin D deficiency and their pain improved when they took vitamin D supplements.
Polycystic Ovary Syndrome and Infertility
Calcium and Vitamin D supplementation helped all the patients with PCOS and infertility after vitamin D deficiency in one small study.
It has long been noted that this autoimmune condition occurs more often at temperate zones, where there is less sunlight exposure. One study showed that calcium, magnesium and vitamin D supplementation helped reduce exacerbations in MS patients. Some researchers and clinicians wonder if supplementation with vitamin D could prevent MS in people living in temperate zones.
Diabetes, insulin resistance, epilepsy, Graves disease, ankylosing spondylitis, systemic lupus erythematosis, obesity, and rheumatoid arthritis are some other conditions that have been associated with deficiency of vitamin D and/or improvement with vitamin D supplements.
Should you take Vitamin D?
Some readers may be wondering whether they might benefit from supplementation with vitamin D and if so, how much they should take. The following are some supplementation recommendations.
- If possible, see your doctor to have your 25-OH-vitamin D levels checked in your blood. This test is considered more accurate than the 1, 25-OH-vitamin D testing. It has been proposed by some experts that the “optimal range” on this blood test should be 40-65 ng/ml. This range is higher than the “normal range” offered by the labs as a reference, but keep in mind that the labs do not necessarily weed out vitamin D deficient people it used to establish the so-called normal reference ranges. If your doctor does not run this test, consider finding an Naturopathic physician or Medical Doctor who is familiar with the new research on vitamin D.
- If your levels are lower than the optimal range, you may benefit from taking vitamin D. Your dosage should depend on your blood level of vitamin D, the amount of sunlight you are exposed to daily and your body size. I have typically recommended dosages of 1,200-4,000 IU for adults. Some experts recommend between 4,000-10,000 IU per day. It may be sufficient to take vitamin D from the late fall through spring and discontinue it in the summer if you allow for 15 minutes of sunshine exposure daily in the summer. If you are taking vitamin D for a specific health complaint, you should know that it may take 3-4 months for your 25-OH-vitamin D levels to plateau, and it is recommended that you continue the vitamin D supplement for 5-9 months to allow for symptom improvement. Please do not supplement with vitamin D if you have excess blood calcium levels, hyperparathyroidism, hyperthyroidism, granulomatous diseases such as sarcoidosis, Crohn’s disease and tuberculosis, certain cancers, or if you are taking drugs that make you more sensitive to vitamin D. Please consult your doctor regarding whether you can or should take vitamin D under your doctor’s supervision.
- Return to your doctor to have your calcium and 25-OH-vitamin D levels checked weekly at first, then monthly during supplementation to assure that you do not overdose. If you experience symptoms of over-dose such as loss of appetite, nausea, vomiting, excessive thirst and urination, itching, nervousness, or elevated blood calcium levels.
- Make sure that you use only a high quality vitamin D3 supplement and not vitamin D2. Vitamin D2, often used also in vitamin D fortified foods, does not raise blood levels of 25-OH-vitamin D effectively and has more potential for adverse effects compared with vitamin D3. I recommend and carry in my office emulsified liquid vitamin D drops called Bio-D-Mulsion by Biotics Research Corp. It is easy to take, inexpensive, and the taste is palatable. Vitamin D is a fat-soluble nutrient, and the micro-emulsification of the liquid vitamin D improves absorption.