The Vitamin Alphabet Begins with “D”

It is common knowledge that healthy eating is an important aspect of one’s lifestyle in order to live longer and have an overall better quality of life.  However, many people are unaware of the various components that are needed.  Consuming ample fruits and vegetables is a key part in addition to getting necessary recommended amounts of vitamins and minerals.  This may be confusing to many people but can be done.

Vitamins are needed to maintain normal metabolism, growth, and development.  They are classified as any group of organic compound, other than proteins, carbohydrates, fats, minerals, and organic salts.  Vitamins are broken up into two categories, water-soluble and fat-soluble.  The difference is that the nine water-soluble vitamins (8 B vitamins and vitamin C) are easily dissolved and excreted from the body.  Since they are not stored, it is important to get them daily.  The four fat-soluble vitamins (A, D, E, and K) are absorbed into the body from the intestinal track.  Since they are stored, it is easier for them to build up to toxic levels, so caution is advised.

Sunshine Vitamin

Vitamin D is essential to maintain normal amounts of calcium and phosphorus in blood.  A major function is to facilitate the absorption of calcium, indirectly helping form and maintain strong bones and preventing osteoporosis in the long run.

Vitamin D is a fat-soluble vitamin not naturally found in many foods.  Fish is a great source to obtain the vitamins. Cheese and egg yolks also contain some vitamin D, but in small amounts.  Although it is not naturally found in a plethora of items, many food companies enhance their products with the vitamin.  For example, during the 1930’s the United States was having a problem with a high population getting rickets so they implemented a milk fortification program.  Doing so essentially eliminated the problem.  Since then, some brands of orange juice, cereal, and yogurt have also added the vitamin to their products.

Interestingly enough, vitamin D is also able to be absorbed through the sun’s rays and is a significant source of how people acquire the recommended amount.  Therefore, it has been nicknamed the Sunshine Vitamin.  Ultraviolet B (UVB) rays come through the clouds and are absorbed by the skin and converted into vitamin D.   The suggested amount of sunlight exposure varies slightly from each source; however, it is thought that as little as ten minutes a day is ample to prevent vitamin D deficiencies.  The time of day, amount of cloud coverage, sunscreen, and season can all affect the amount absorbed.  People living above the 42 degree north latitude line, which crosses from Boston to the northern border of California, will not be able to absorb the recommended amount from November until February.  During this time it is important for those individuals to make sure they get the adequate amount from their diets.

How much do I need?

If you take a multivitamin it is most likely you get anywhere from 50 – 1,000 International Units (IU).  The Adequate Intake level established by the U.S. Institute of Medicine of the National Academy of Sciences is 200 IU for those males, females, and pregnant/lactating women under the age of fifty.  Individuals 50-70 years of age are recommended to have 400 IU daily while those over 70 years-old are suggesting having 600 IU per day.  The upper limit for vitamin D in infants under one year is 1,000 IU per day and increases to 2,000 IU per day after turning one year.  This limit is important to follow because when taking doses that high it is possible for hypercalcemia (high blood calcium levels) to occur, along with other toxicities.

As stated previously, the recommended amount is the same for women who are pregnant or lactating.  However, it is important to keep in mind that in breastfeeding, the breast milk is low in vitamin D.  To prevent your child from having a deficiency supplementing may be necessary, starting within the first couple months after birth.  Be sure to consult with your physician to make necessary changes in diet.

What if you do not have enough?

Not obtaining enough vitamin D through diet, supplements, or UVB rays can lead to deficiency diseases.  Skeletal deformities caused by rickets are common in children, while adults suffer from osteomalacia, or weakness in muscles and bones.  Those at risk include the elderly, exclusively breastfed infants, obese individuals, along with people with limited sun exposure.  Being conscious of the amount of vitamin D in the foods you eat, getting enough exposure to sunlight along with considering taking a multivitamin are all key factors in making sure you get the recommended amount of vitamin D.

Thank you to Stephanie Perez, Dietetic Student at Michigan State University for preparing this article on behalf of Reconnect with Food at Inner Door Center.

Ask the Doctor: January 2008

Question: I was watching Oprah and Dr. Oz mentioned that his favorite vitamin was vitamin D, and that a lot of people don’t get enough vitamin D. Why is that? I thought we got enough vitamin D from milk and the sun. – D.V., Grand Blanc

Answer: That is a great question! This topic has come up in a lot of conversations between me and my colleagues recently, and I agree with Dr. Oz. Vitamin D has been underrated for sometime.

The most common way that we get vitamin D is from the sun. When the sun hits your skin, it starts the production of vitamin D. Because of the shorter days and decreased intensity of the sun in the northern states and Canada, people living there (including the Detroit metro area) are more likely to be vitamin D deficient. Also, with the concern about skin cancers increasing, more people are using sunscreen and thus preventing the formation of vitamin D in the skin. Most dermatologists recommend a sunscreen with at least an SPF of 15 to prevent skin cancer; however an SPF of 8 will block enough of the sun’s rays that your skin will not make vitamin D.

Vitamin D can also be obtained through the diet. As most people know, milk is fortified with vitamin D. However, the vitamin D in milk breaks down easily, and by the time you have consumed about half of the milk in the carton, the vitamin D is no longer there. The other source of vitamin D in food is fatty fish like salmon or tuna. Of course, salmon and tuna contain many other important nutrients, like omega-3 fatty acids, so anytime you can eat these fish is good.

You can also get vitamin D from your multivitamin or over-the-counter supplement. Most doses of vitamin D in multivitamins are based on the recommended daily allowance, which we are now realizing is too low. The current recommendations for daily vitamin D intake was based on the amount of vitamin D needed to prevent rickets in children, which is not enough to prevent a variety of problems in adults.

The reason that we are so concerned about vitamin D now is that it is related to many common and serious illnesses. Vitamin D deficiency contributes to osteoporosis in post-menopausal women and can explain why some women still have hip fractures even when they are on medications to prevent fractures.

Vitamin D deficiency can cause muscle weakness and may contribute to the symptoms of arthritis. Vitamin D deficiency can also make the achiness that comes with the cholesterol medications known as “statins” worse. Before you stop your cholesterol medication because of aches and pains, ask your doctor to check your vitamin D level and replace the vitamin D if necessary. Your aches should improve as your vitamin D level goes up.

Vitamin D helps to keep cells healthy, and a vitamin D deficiency is linked to an increased risk of cancer. Those cancers that can be affected by vitamin D levels are colon, pancreatic, prostate, ovarian, and breast cancer. The risk of Hodgkin’s lymphoma is also increased by low levels of vitamin D. Vitamin D deficiency increases the risk of diabetes type 1, crohn’s disease and multiple sclerosis. Low levels of vitamin D can increase the risk for heart disease by mildly increasing blood pressure and increase inflammatory markers that are linked to heart disease, such as C-reactive protein.

Vitamin D deficiency can also contribute to depression. One of the theories behind seasonal affective disorder is that it is related to low vitamin D levels in the winter months. Seasonal affective disorder is related more to the amount of light during the day rather than the temperature, so the vitamin D theory may hold to be true.

The next time you go in for a physical or for blood work with your doctor, ask about having your vitamin D level checked. The normal range currently is 20-80, with anything below 10 considered to be severe deficiency. However, we find that people do better with levels higher than 20, so I treat my patients who have vitamin D levels less than 32. With clinically deficient patients, I am replacing their vitamin D aggressively with 50,000 IU once a week for 8 weeks, and then repeating the level check. Once the vitamin D level is above 32, the 50,000 IU tablet only needs to be taken once a month.

If you are vitamin D deficient, you will need to take supplements for the rest of your life. Over the counter formulations of vitamin D come in 1000 IU tablets. The 50,000 IU tablet is available by prescription from your pharmacy. Once you are back into the normal range, you could also take two over-the-counter tablets daily instead of the prescription monthly dose.

If you are not vitamin D deficient, taking the over the counter formulation once or twice a day can help you maintain your healthy levels. It is almost impossible to overdose on vitamin D, so if you want to take the supplement before having your level checked, go ahead. Taking vitamin D is an excellent way to prevent a number of serious diseases with a simple natural supplement a day.

Dr. Karen D. Lockwood is board-certified in Internal Medicine and is currently in private practice in Troy, MI.

If you would like to submit a medical question to Dr. Lockwood, please email your question to: askthedoc@healthandleisureonline.com

* Advice found within this article is for informational purposes only and should not replace the advice or recommendations of your physician.