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If you are like an increasing number of us, the answer is surprisingly, “Yes,” at least when it comes to the critically important nutrient, vitamin D.I am amazed at how often I discover patients with low levels of vitamin D. The problem is not solely with our diets, which is certainly responsible for much of the illness we Americans suffer; rather our chronic lack of exposure to the sun. Vitamin D is produced via a photochemical reaction in the skin that involves the sun’s ultraviolet rays (UVB). We spend most of our waking hours indoors away from the sun’s rays over the course of a year, despite the many hours we may spend outside in the summer months. Compounding the problem, our “outdoor” season is rather short, and when we are outside during those few short months, thanks to many decades of advice concerning the risks of skin cancer, we protect ourselves from the sun with sunscreen. And finally, we live in a northern climate in which the angle of the sun is relatively flat to the earth’s surface, meaning that the sun exposure we receive does not produce the same amount of vitamin D as it would in more southern locations.

All of these factors, combined with a typical American diet that is low in vitamin D has lead to a vitamin D deficiency epidemic of sorts.

How much vitamin D does the average adult need?
Adults age 25-50 years need at least 400 i.u. (“International units”) per day. Those over age 50, and particularly postmenopausal women, require 600-800 i.u. per day, although experts disagree on the amounts. In fact many experts, recommend at least 1,000 i.u per day for women over age 50. Many wellness experts are now recommending at least 5,000 i.u. as a daily supplement. Personally, I take 5,000 i.u. per day, but you should discuss the appropriate supplementation with your physician.

What are common dietary sources of vitamin D?
This critical vitamin is found naturally in only a few foods like fatty fish (e.g., salmon), liver and cod liver oil, and egg yolks. For example, Salmon contains 500 i.u per 3 oz. serving; eggs contain 25 i.u. per yolk; and vitamin D enriched milk products contain 100 i.u per 8 ounces. Many vitamin D fortified foods, including many types of milk, cereal, bread, and orange juice, are now widely available.

How does the body use vitamin D and what are the effects of a vitamin D deficiency?

Vitamin D is produced in the skin via a photochemical reaction with ultraviolet radiation (UVB) from the sun, and it is the principle regulator of calcium metabolism. As a result of its role with calcium, vitamin D is best known as an important tool in the prevention and treatment of osteoporosis. Other conditions with links to this essential nutrient include:

  1. Vitamin D is essential to a healthy immune system, and those with optimal levels in their blood can expect fewer, colds, flu, and other infectious problems.
  2. Vitamin D is a cancer fighter: it promotes several processes at the cellular level that inhibit malignant transformations.
  3. Vitamin D is a potent anti-inflammatory agent. Chronic inflammatory processes are involved in certain types of heart disease. It’s anti-inflammatory properties are the reason it can be very useful in treating several types of musculoskeletal pain disorders including fibromyalgia and rheumatoid arthritis.
  4. Vitamin D is a potent fighter against diabetes (type I and II), hyperglycemia, and insulin resistance. Diabetes is often associated with low vitamin D levels. And the pancreas requires adequate vitamin D to produce and secrete insulin
  5. Vitamin D helps lower blood pressure in those with high blood pressure
  6. Vitamin D may have a role in the prevention of preterm labor and pre-eclampsia

Increasingly, researchers are discovering new links to vitamin D in numerous diseases and conditions. Lowered vitamin D levels have been discovered, and therefore vitamin D supplementation may be therapeutic, in several conditions including:

  • Acne
  • Adrenal insufficiency
  • Allergies
  • Alzheimer’s disease
  • Arthritis
  • Asthma
  • Autism
  • Autoimmune disorders
  • Bacterial infections
  • Bones weak (easy to fracture)
  • Breast cancer
  • Cancer (all types)
  • Celiac disease
  • Colds and ‘flu
  • Crohn’s disease
  • Chronic fatigue
  • Chronic obstructive pulmonary disease
  • Chronic pain
  • Colonic adenoma
  • Colorectal cancer
  • Cystic fibrosis
  • Dementia
  • Dental cavities and misaligned teeth
  • Depression
  • Diabetes Fatigue
  • Gluten intolerance
  • Graves disease
  • Heart disease
  • Hypertension
  • Influenza
  • Kidney Disease
  • Low back pain
  • Lupus erythematosis
  • Melanoma
  • Mental illness and mood disorders
  • Multiple Sclerosis
  • Muscle weakness and pain
  • Obesity
  • Osteo-arthritis
  • Osteomalacia (softening of bones)
  • Osteoporosis
  • Ovarian cancer
  • Parkinson’s disease
  • Periodontal disease
  • Peripheral artery disease
  • Pelvic floor disorders
  • Pneumonia
  • Post-operative infections
  • Psoriasis
  • Rheumatoid arthritis
  • Rickets
  • Seasonal affective disorder (SAD)
  • Sepsis
  • Tuberculosis
  • Urinary incontinence
  • Viral infection

What about tanning beds as a substitute for sun exposure in the production of vitamin D?

In theory, one would assume that a tanning bed would be a perfect substitute for sun exposure when it comes to vitamin D. However, the answer is more complicated. There are two types of ultraviolet radiation related to sun exposure and tanning: UVA and UVB. UVB is more responsible for the typical sunburn and reddened skin, where as UVA is more responsible for the golden brown skin tone that so many of us desire. As luck would have it, only UVB produces the photochemical reaction that generates vitamin D. Most tanning salons promote beds that limit UVB exposure in favor of the more appealing results seen with UVA exposure. So the real answer is unclear. It depends on the specific facility and its equipment. With dietary supplementation so readily available, inexpensive, and easily tolerated, it is difficult to recommend potentially skin-damaging ultraviolet exposure in the name of vitamin D. Many researchers are looking into this question, so stay tuned for more information as it becomes available.

What is the take-home message about vitamin D supplementation?

From my perspective, we cannot overlook the many benefits of vitamin D supplementation. Regardless of your diet or the amount of time you spend in the sun, if you are not taking a vitamin D supplement, you probably should be.

If you are uncertain if you should take a vitamin D supplement, or of the amount you should take, I’m happy to discuss your specific needs with you. A thorough evaluation may involve a blood test to evaluate your vitamin D level as well as an assessment of your overall risk for several conditions.