What is Vitamin D?

Vitamin D is often known as the sunshine vitamin as it is synthesized when sunlight, specifically UV-B rays, comes in contact with skin.  Vitamin D technically acts as a hormone, affecting skeletal and extraskeletal tissues, calcium homeostasis and bone formation, cellular proliferation and differentiation, immune system function, vascular walls, and the endocrine system.1,2,3  Intake of vitamin D supplements is associated with decreases in mortality (death).1


Cancer, Heart Disease, Diabetes, Autism and Vitamin D

Vt. D deficiency has been linked to various health problems including autism, depression, 17 varieties of cancer, heart disease, stroke, hypertension, autoimmune diseases, diabetes, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, a higher risk of falls, birth defects, and periodontal disease.1,2,3  Many studies have linked Vt. D deficiency to increased rates of multiple sclerosis.1,2,3,4,5


Sources of Vitamin D

The most efficient way to get vitamin D is by sun exposure.  But be warned; adequate sunshine without getting burned is the key.  During late spring, summer, and early fall, for light-skinned people, aim for three 20 minute sessions per week without sunscreen with as much of your skin exposed as you can.3  If you have sensitive skin, start with shorter exposure time in the late spring and build up gradually.  Dark-skinned people need 3-6 times longer exposure, and some believe vitamin D deficiency may be associated with higher rates of cancer among African Americans.  Check with your doctor if he/she is knowledgeable about sun exposure and vitamin D, especially if you are sun-sensitive.  Studies indicate human breast milk contains inadequate levels of vitamin D, so routine vitamin D supplementation is advisable for breast-fed infants who are deprived of sunlight exposure.2


What to do when Sunshine Won’t Work

Unfortunately most of us living in the US are not able to get adequate sunlight exposure for much of the year.  If you live in northern US states (above 35 degrees latitude, most of the country), the sun is too low in the sky to be effective, and it is too cold to expose most of your skin.  Other choices are tanning beds with UVB bulbs, or supplements.  If you decide to use UVB bulbs, please read about it before you begin, and check with your doctor, especially if you have sensitive skin.  Dr. Mercola’s site, mercola.com, has several articles regarding tanning beds and bulbs, and concerns about radiation and EMFs from bulbs.  Therefore, most of us have to rely on vitamin D supplements.  Vitamin D fortified foods often use vitamin D2, which is less effective as vitamin D3.  Oily fish, eggs and butter have some Vt. D, but not enough.


Vitamin D testing

Before you begin taking vitamin D supplements, have your blood level of 25(OH)D (25 hydroxyvitamin D) tested by your doctor, or you can order testing kits online at VitaminDCouncil.org.  You may be told that “normal” levels are 20-40 ng/ml, but you should strive to keep your 25(OH)D level at 50 ng/ml or higher year round.2,3  You can get 20,000 IU/day from 20-30 minutes of sun exposure, so supplementing with 1,000 IU/day or more should not be a problem.  Again, you should have your 25(OH)D level checked and rechecked a few times a year.


Vitamin D3 Supplements

An editorial in the Archives of Internal Medicine stated “…it seems prudent that physicians suggest supplementation [of vitamin D].” 1  Make sure you are taking a vitamin D3 (cholecalciferol) supplement, not vitamin D2 (ergocalciferol, synthetic).  The editorial also stated taking 800 IU/day of vitamin D would not achieve the healthy goals; those with minimal sun exposure may need 1000-2000 IU/day.


Dr. Fuller’s Recommendations

First, have your level of 25(OH)D checked by your physician and tell your doctor you will be taking vitamin D supplements. If there is a delay before your blood test, consider taking 1,000 IU of vitamin D3 per day.  Vitamin D supplements are inexpensive; one brand I sell in my office is $12 for 250 softgels, 1,000 IU each.  If you live in a sunny southern state and sunbathe a couple of times a week during peak hours as previously described, you probably don’t need vitamin D supplements and absolutely should have your 25(OH)D level checked first.  If you live in a northern area, follow the sun exposure recommendations above when possible.  If you are light-skinned and are getting three 20 minute sun sessions per week, don’t take vitamin D supplements unless you have a demonstrated deficiency of 25(OH)D and are working with a knowledgeable doctor.  MS patients may need much more than 1,000 IUs of vitamin D per day, depending on blood 25(OH)D levels.  MS prevention and treatment also require fish oil and antioxidants; read more below, and work with a knowledgeable doctor.


Medical Clinic in Boston Tests Patients for Vitamin D levels and Recommends Vitamin D Supplements

Dr. Azzie Young is president of the Mattapan Community Health Center near Boston.  Her doctor tested her blood level of vitamin D, and the 25(OH)D result was 12 ng/ml, a very low level.  She takes 3,000 IU of vitamin D3 per day, and now her level is 40 ng/ml.  After taking vitamin D supplements and increasing her 25(OH)D, Dr. Young notices she feels wonderful; she can bounce out of a chair, she is walking without problems and she sleeps better.  It has made a big difference in her life and she is trying to spread the word nationwide.  Patients at this clinic are regularly tested for vitamin D levels and are educated about vitamin D3 supplements.6


Vitamin D and the Flu

Studies indicate vitamin D is essential for immune system function.1,2,3,4,5,8  Vitamin D levels tend to be the lowest in the winter months, during flu season.  It makes sense to take vitamin D supplements during the winter months to help strengthen your immune system to try to decrease your susceptibility to the flu.  I also recommend ongoing wellness chiropractic care to help improve your immune system, and many report fewer colds and flus with chiropractic care.

Regarding the flu shot, I recommend you read about it before getting one.  I have articles on my website and in my office about the flu shot, and additional information is available on Mercola.com and nvic.org.


Vitamin D and Osteoporosis

Some studies indicate vitamin D is more important than calcium in providing protection against osteoporosis.7  Results suggest if vitamin D status is sufficient as previously explained, you may only need 800 mg/day of calcium supplements to maintain a healthy calcium level.7  Of course, exercise (especially weight bearing resistance exercise) is very important to help prevent (and improve) osteoporosis along with good eating habits and supplements.


Use Vitamin D Along with other Supplements and Healthy Habits

Vitamin D is not the cure-all, but it may be exactly what some of you need.  I recommend vitamin D supplements along with fish oil (see my All about Fish Oil newsletter) and antioxidants.  Remember, supplements do not replace good eating habits; they only supplement them.  Eat as much fresh, organic, locally grown vegetables and fruit as you can.  If you eat meat, please eat organic turkey, chicken and beef as much as you can, and keep your servings small (palm of your hand size).  There are other organic meats available; look online.  Avoid processed food, soda, sport drinks, juice, and caffeine as much as possible.  Use good eating habits in conjunction with wellness chiropractic care and regular exercise.  Keep a health diary, even if for brief entries every day or week.  It provides a great record of what strategies have worked to improve your health and wellness.

Remember, chiropractic care focuses on health and wellness, and may help the function and performance of your nervous and immune systems.  I recommend ongoing wellness and maintenance chiropractic care for babies, children, adults and the elderly, along with good eating habits and vitamin D, fish oil, and antioxidant supplements.



Thanks to Dr. Dan Murphy, DC; Dr. Robert Melillo, DC; Dr. Mercola; LOE.org (Living on Earth); NPR & WBUR 90.9 FM Boston; Boston University; VitaminDCouncil.org; emersonecologics.com.  Written December 2008.



1. Vitamin D Supplementation and Total Mortality, Archives of Internal Medicine, Sept. 10, 2007; 167:1730-173 Philippe Autier, MD; Sara Gandini, PhD

2. VitaminDCouncil.org

3. Mercola.com; multiple articles on Vitamin D, sunlight, tanning beds

4. Vitamin D intake and incidence of multiple sclerosis, Neurology, January 13, 2004; 62:60-65.  K.L. Munger, MSc, S. M. Zhang, MD ScD, E. O’Reilly, MSc, M.A. Hernan, MD DrPH, M.J. Olek, DO, W.C. Willett, MD DrPH, A. Ascherio, MD DrPH

5. Serum 25-Hydroxyvitamin D Levels and Risk of Multiple Sclerosis, JAMA, Dec. 20, 2006; pp. 2832-2838

6. LOE.org     http://www.loe.org/shows/segments.htm?programID=08-P13-00044&segmentID=4

7. Emersonecologics.com, 2008; articles from JAMA, NEJM, Osteoporosis, and Preventing and Reversing Osteoporosis

8. Boston University report, 2-20-08, and the Boston Medical Center, bmc.org.