Archive for Nutrition
Water is the elixir of life, but do we get enough of it? Many people think that substituting sodas, coffee and juice for water is enough to keep us hydrated and healthy, but nothing can beat the original and the best – water. Our bodies are made up of 43-75% water, and it’s an essential component of our health. The wide range in percentages comes from measuring different populations ranging from newborns (~75%) to obese people (~45%), with normal adult hydration at about 57-60%. We can survive a month without food, but we’ll die after a week without water. The body is able to absorb many nutrients and salts better thanks to water’s ability to transport these nutrients and oxygen to our body’s cells and organs. Detoxifying is vitally important to our health, since it cleans our bodies of impurities. The best way to excrete these impurities is through urine and sweat – both of which depend on our water intake. Upping your water intake may help to reduce the risk of kidney stone formation. The kidneys filter our waste products through the blood and out via urination. If the concentration of salt in our urine is high, and our water content low, this increases the risk of kidney stone formation. By drinking more water, this concentration of salts is reduced. We are at risk of sunstroke if our bodies become dehydrated. When we sweat, this cools our body down.
If dehydrated, the body cannot sweat and overheats, which can damage the body’s internal organs. If you suffer from high blood pressure, maybe it’s your water intake that is the problem. When our bodies excrete and lose more than the optimal amount of liquid, our blood vessels constrict, which can cause our blood pressure to increase. If blood pressure is increased by a deficiency in water, this may also increase the risk of heart disease. Because the constricted blood vessels cause an increase in blood pressure, the heart works harder to compensate for the reduced volume of blood. Lower blood pressure and greater consumption of water help lower stress on the heart. What’s more, drinking more water can help you stay younger looking. Drinking a lot of water helps keep the skin clean and fresh-looking by removing impurities through sweating. Water also helps to keep the skin hydrated, which means younger looking skin – sagging and wrinkled skin is usually a sign of dehydration. Drinking water also cuts hunger pangs and acts as a good filler. Water has zero calories, so consider trading in your sugary drinks and juices to help control your weight. If increasing your water intake seems like a chore, why not add lemon or mint to your bottle to make it taste better? Eat more fruits rich in water such as watermelon, and try to drink water more regularly over the course of the day. Having a glass of water or water bottle near you during the day has been shown to increase water consumption without effort.
References Used  http://www.jbc.org/content/203/1/359.full.pdf Accessed October 2011  http://thetaoofgoodhealth.com/10-health-reasons-why-you-should-drink-more-water-4/ Accessed October 2011  http://www.uihealthcare.com/topics/generalhealth/ghea5288.html Accessed 2011
Do you know the difference between high glycemic foods and low glycemic foods? If you’ve ever felt light-headed or shaky (and very hungry) a few hours after eating certain foods, then you’ve experienced the “roller-coaster ride” of high glycemic foods. You’ve probably noticed that all foods don’t have this effect on you, and those that don’t are most likely low glycemic foods. The Glycemic Index or GI is a scale that ranks high-carbohydrate foods according to how much they raise your blood glucose levels after eating. The GI ranges from 0 to 100. Foods with a high GI are digested quickly and cause a significant spike in our blood sugar levels. This increase in blood sugar causes a corresponding increase in insulin to bring those sugar levels back down. Low glycemic foods have less of an impact on your body because they are digested and absorbed more slowly, so you need less insulin to control your blood sugar levels. When sugar and insulin aren’t spiking, you won’t get that light-headed or weak feeling. You just feel normal. There are many more advantages to choosing a low glycemic diet.
Low glycemic foods are beneficial to our health because controlling blood sugar and insulin levels is one of the keys to reducing our risk of heart disease and diabetes. Low GI diets are also useful for controlling our appetite and aiding in weight loss. When our blood sugar levels are maintained relatively stable, our bodies perform better. A study from the Harvard School of Public Health demonstrated that high GI diets are strongly linked to an increase in the risk of Type II diabetes and heart disease. The World Health Organization recommends that people in developed countries eat as many low-GI foods as possible, to prevent heart disease, diabetes, and obesity. A hundred years ago, our foods simply took longer to digest. They came straight from the farm to our table, in its natural state, containing the original fiber and other natural components they were grown with. Modern food processing practices have stripped our food of many of its natural properties, making it easy to package and store, and extremely quick to digest. And the faster we digest the food, the quicker we get hungry again. This is the “roller coaster” that happens when we consume too many high GI foods.
High glycemic index foods may give you a burst of energy, but this is followed by a “crash” as the insulin takes the blood sugar back down and you feel hungry again. To make things worse, these insulin spikes turn all that excess blood sugar into fat, which is usually stored right around the abdomen. On the other hand, when we consume low glycemic foods such as fruits, vegetables, legumes and whole grains, the rise in blood sugar is slower and more sustained over time. That means you feel fuller longer and are less tempted to eat again so soon. Our energy levels are maintained throughout the day, which not only provides health benefits but also makes us feel better, because we’re not on that up and down cycle from morning to night. If you would like to increase your consumption of low glycemic foods, here are some suggestions.
Eat less of the following:
• Avoid sugary snacks, especially those made with refined sugar. Not only are they high GI foods, they are mostly empty calories.
• Many salad dressings are very high GI foods. • While potatoes are nutritious, especially with their skins intact, they are also very high GI foods.
Eat more of the following:
• Fruits and vegetables in their natural state, preferably organic. Many commercially grown fruits and vegetables have a higher sugar content than organic. Commercially grown foods also have added chemicals and pesticides.
• Eat foods with lots of fiber, which tends to lower the glycemic index of everything you eat.
• Choose breakfast cereals with whole grain barley, bran, and oats. Interestingly, the cooking method can affect the GI rating of a food. For example, boiled potatoes are rated an 81 on the glycemic index, while baked potatoes rate as 119 and mashed potatoes 104.
However, rather than obsess about individual GI food ratings, remember that the most important goal is to have a low glycemic diet overall. Eating the occasional high GI food is OK, especially if you also eat a low glycemic food along with it. Try to focus on eating a healthy, balanced diet including a wide variety of whole, natural, and fresh foods. By doing so, you won’t even have to consult the GI scale, because you’ll be eating a relatively low glycemic diet and gaining all the benefits described here.
You’ve probably heard that trans fats are bad for you. You may even be looking for them on product labels. But what about all the foods that don’t have nutrition labels on them, such as French fries or doughnuts? When it comes to these foods, trans fats may be hiding in plain sight. That’s why it is important for you to have a basic understanding of where you are most likely to encounter them. By knowing a little more about trans fats, you can make more informed food choices. Trans fats, also known as trans fatty acids, come from the hydrogenation of polyunsaturated oils and are used in place of healthier oils in many foods. Say what?
Unless you majored in chemistry, that probably makes zero sense to you, so allow me to explain. Naturally occurring vegetable oils – such as canola, sunflower, or corn oil – don’t contain any trans fats. People have to intentionally create trans fats. So if we know they are bad for our health, why do we do it? There are several reasons – all of which serve the needs of the food industry, not individuals.
• Increase the shelf life of products
• Make vegetable oils more suitable for repeat use in deep fryers
• Decrease product refrigeration requirements
• Are less expensive than butter or lard Have you ever noticed that butter is stocked in the refrigerated section of grocery stores, but packaged baked goods like muffins aren’t? Yet the muffins still resist spoiling.
Why? It’s because the kinds of pure vegetable oils and butter we cook with at home are often substituted with trans fats when foods are prepared on a commercial scale. The trans fats come from adding hydrogen atoms (partially hydrogenating) to unsaturated fats. This process raises the melting point of the fat – so that it will be more solid at room temperature and won’t require refrigeration to hold its shape. Up until 2006, food manufacturers were not required to list trans fats on product labels. Now the FDA requires food manufacturers to list the presence of trans fats. And although the FDA did not set any limits on the amounts of trans fats that are allowed to be present in our foods, they did say that it should be “as low as possible.
Experts believe that there are nearly 50,000 products on the market that contain trans fatty acids. While the term “trans fats” might not specifically appear on the nutrition label, you will see terms such as shortening and hydrogenated or partially hydrogenated oil. The closer to the top of the nutrition label these trans fats appear, the higher the percentage that are present. Consumer health groups have begun to pressure food manufacturers to remove trans fats from their products altogether. Some have gone so far as to file law suits demanding that a particular product be removed from the shelves unless trans fats are eliminated from the ingredients. While that battle is fought at the highest levels, individuals can take control of their own health by recognizing the types of food likely to contain high levels of trans fat. Stay on the lookout for trans fats in fried foods, in unrefrigerated baked goods and in snack foods such as cookies and crackers.
Bibliography Dietary Fats Explained MedlinePlus Medical Encyclopedia. (n.d.). Retrieved 9 5, 2011, from MedlinePlus Health Information from the National Library of Medicine: http://www.nlm.nih.gov/medlineplus/ency/patientinstructions/000104.htm Trans fat. (n.d.). Retrieved 9 5, 2011, from Wikipedia.org: http://en.wikipedia.org/wiki/Trans_fat Trans fat definition Cholesterol Information Produced by Doctors For Patients Experiencing High Cholesterol Levels. (n.d.). Retrieved 9 5, 2011, from MedTerms.com: http://www.medterms.com/script/main/art.asp?articlekey=11091
Have you ever found yourself tuning out information about nutritional supplements because it all seems confusing and contradictory? If yes, you are not alone. One headline says ‘get more X’ the next headline says ‘be careful about too much X’ and another says ‘X supplementation not necessary at all’. Headlines are meant to sell newspaper and magazines. They report on what’s new not necessarily what is backed by the most evidence. And, the stories are often selected based on findings that are contrarian or against conventional wisdom. After all, who is going to buy a magazine with the headline, “No change in guidelines – eating more plant-based foods is still good for you.”
Consumers really need a reliable source of evidence-based recommendations for nutritional supplements. Since these are not regulated by the FDA, there isn’t a government run website that you can count on to be unbiased. There are several private companies, non-profits and even individuals that claim to offer comprehensive unbiased information on nutritional supplements, but who has the time to sift through all of these to figure out whose information is the best?
At the risk of offending a number of other great sources, this article is a plug for the Linus Pauling Micronutrient Information Center at Oregon State University at http://lpi.oregonstate.edu/infocenter. Chances are this is a source you’ve never heard of or looked at, but you should.
The website describes the Linus Pauling Institute as a “source for scientifically accurate information regarding the roles of vitamins, minerals, other nutrients, dietary phytochemicals and some foods in preventing disease and promoting health”. As you can see from the description, their mission extends beyond nutritional supplements to also include whole foods. This is critically important because sometimes nutrients are more potent together (as in a food) than they are separately.
When you visit the website, you’ll have a chance to subscribe to the newsletter near the top of the page. Do it. This isn’t another email newsletter but rather a printed, bound newsletter sent to your house containing all of the Institute’s latest research.
The folks at OSU are doing excellent work to bring us all trustworthy, evidence based recommendations on the tens of thousands of nutrients in our foods. Take some time to look at their website, bookmark it and share it with others. If there are concepts or terms you don’t understand, feel free to ask us during your next appointment or send us an email.
The B group of vitamins is probably the most commonly misunderstood of the vitamins, simply because the B vitamins are several distinct vitamins lumped together. Additionally, the fact that the vitamins in this group are known by both letter, number and name is confusing to many people.
Here is a quick list of the B vitamins found in the Vitamin B complex group
• B1 is also thiamin
• B2 is also riboflavin
• B3 is also niacin
• B5 is also pantothenic acid
• B6 is also pyridoxine
• B7 is also biotin
• B9 is also folic acid
• B12 is also cobalamin
You should note that there are four additional substances in the B complex group, though they are not known as vitamins. They are choline, lipoic acid, PABA and inositol. When you purchase B complex vitamins, these four will not be included. Furthermore, one or two of the recognized B vitamins may also be omitted. B5 and B7 are so widely available in food that most people get plenty of these vitamins even if they aren’t eating a healthy diet. There are gaps in the numbers of the B vitamins because our understanding of them has evolved over time. Initially there was only a single B vitamin. Later it was recognized that what had been referred to as a single vitamin, actually had many components. These component parts where numbered 1,2,3,4, etc…
Even later it was determine that some of these components (such as B4) did not meet the criteria of being a vitamin and they were dropped. That’s how we ended up with 8 B-vitamins with non-sequential numbers. One thing that all the B vitamins share is that they are water soluble. Any excess vitamin B is not stored, but rather is excreted in the urine. That means that all the B vitamins need to be constantly replenished from our diets. B vitamins are found in whole unprocessed foods including grains, meats and vegetables. In general, the more processed that food is, the lower the content of all the B vitamins. A daily multi-vitamin is a great way to ensure that you are getting all the B complex Vitamins your body needs on a daily basis. One of the most commonly recognized uses of the B vitamins is an energy booster. Many popular energy drinks that claim a natural boost of energy without sugar or caffeine are high in B vitamin complex. There are too many components in the Vitamin B complex to discuss the health benefits, deficiencies and Recommended Daily Allowance for the whole group in a single article. Look for future articles about each of these important nutrients. If you have questions about your current nutrition and supplement plan, just ask. We are here to help!
Bibliography B Vitamins MedlinePlus. (n.d.). Retrieved 8 10, 2011, from National Institutes of Health: http://www.nlm.nih.gov/medlineplus/bvitamins.html Micronutrient Information Center. (n.d.). Retrieved 8 11, 2011, from Linus Pauling Institute at Oregon State University: http://lpi.oregonstate.edu/infocenter/vitamins.html
Perhaps the most well-known vitamin, and one that is frequently cited as vital to good health, but what is Vitamin C exactly? Vitamin C or L-ascorbic acid is a key nutrient and antioxidant essential to our diet. When our bodies contain more free radicals than antioxidants, our bodies are said to be under oxidative stress . Health issues that can arise from oxidative stress include hypertension, cardiovascular disease, chronic inflammatory disease and diabetes [2,3,4]. Vitamin C can help to protect the body against oxidative stress, by raising the levels of antioxidants in the body.
Many animals can synthesize Vitamin C in their bodies; however, humans have lost the ability to do so. One possible reason is that rapid evolutionary changes in humans caused us to lose the capability to produce our own Vitamin C supply [5,6,7], so we must stock up on the Vitamin through the consumption of fruits, vegetables and meats. Because our bodies can only store certain quantities of Vitamin C, it needs to be consumed on a regular basis, or diseases associated with Vitamin C deficiency such as scurvy may develop.
However, scurvy is no longer a health issue associated with modern day Western society, since sufficient quantities of Vitamin C are consumed in a diet rich with vegetables and fruits. If this is the case, then why is Vitamin C still so important? There are other chronic diseases associated with low consumption of Vitamin C such as cancer, heart disease and cataracts. One study found that in order to protect the body against these diseases, a daily intake of 90-100mg is required, higher than the 45mg prescribed against scurvy . In addition to its antioxidant properties, Vitamin C has been found in high concentration in immune cells and it is consumed quickly during infections. It is also a natural antihistamine, preventing histamine release in the body and also detoxifying histamines already present in the body.
This process can be helpful to people who suffer allergies or asthma. One study found that 2g of Vitamin C per day reduced levels of histamine in the blood . The National American Dietary Reference Intake recommends a daily consumption of 90mg-1g per day . The most effective method of keeping our Vitamin C levels high is through a healthy diet. Most fruits and vegetables, such as citrus fruits and rose hips, are very high in Vitamin C, and some meats, such as liver, also contain a good quantity. The extra intake of Vitamin C through supplements is not necessary for healthy adults who eat a balanced diet; however it is recommended for pregnant women, smokers and those under stress.
 McGregor, GP; Biesalski, HK (2006). “Rationale and impact of vitamin C in clinical nutrition”. Current opinion in clinical nutrition and metabolic care 9 (6): 697–703.  Kelly, FJ (1998). “Use of antioxidants in the prevention and treatment of disease”. Journal of the International Federation of Clinical Chemistry / IFCC 10 (1): 21–3.  Mayne, ST (2003). “Antioxidant nutrients and chronic disease: use of biomarkers of exposure and oxidative stress status in epidemiologic research”. The Journal of nutrition 133 Suppl 3: 933S–940S.  Tak, PP; Zvaifler, NJ; Green, DR; Firestein, GS (2000). “Rheumatoid arthritis and p53: how oxidative stress might alter the course of inflammatory diseases”. Immunology today 21 (2): 78–82.  Challem, J; Taylor, EW (1998). “Retroviruses, Ascorbate, and Mutations, in the Evolution of Homo sapiens”. Free Radical Biology and Medicine 25 (1): 130–2.  Bánhegyi, G; Braun, L; Csala, M; Puskás, F; Mandl, J (1997). “Ascorbate Metabolism and Its Regulation in Animals”. Free Radical Biology and Medicine 23 (5): 793–803.  Stone, I (1979). “Homo sapiens ascorbicus, a biochemically corrected robust human mutant”. Medical Hypotheses 5 (6): 711–21.  A.C. Carr, B. Frei, “Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans”, American Journal of Clinical Nutrition, Vol. 69, No. 6, 1086-1107, June 1999.  Johnston, Carol S.; Martin, L. J.; Cai, X. (1992). “Antihistamine effect of supplemental ascorbic acid and neutrophil chemotaxis”. Am Coll Nutr11 (2): 172–176.  http://web.archive.org/web/20080529070818/http://www.iom.edu/Object.File/Master/7/296/webtablevitamins.pdf Accessed October 2011
You may have heard from your grandma that eating carrots can improve you vision. That may not be exactly true, but carrots do contain something called provitamin A carotenoids. These are pigments in some plants that can be converted by the body into vitamin A, and vitamin A is important to your vision.
Vitamin A is also helpful to bone growth and your immune system. As with other vitamins, there are different forms of vitamin A. One of the forms that is most usable to the body is called retinol, which is found in liver, eggs, and milk. One of the most common provitamin A carotenoids that the body converts easily to retinol is beta carotene. Beta carotene is found in yellow and orange fruits and vegetables including carrots, sweet potatoes, spinach, and cantaloupe. Vitamin A is also one of the vitamins often used to fortify breakfast cereals.
Vitamin A is fat soluble, which means that the body stores it, mostly in the liver. That also means that it is possible to build up toxic levels of Vitamin A. This rarely happens from food sources because as the body builds up supplies of vitamin A it will slow down the conversion of beta carotene. When people do get vitamin A toxicity, it is usually from taking too much in supplemental or pill form. Toxic levels of vitamin A can cause liver problems, central nervous system problems, deterioration of bone density, and birth defects.
True deficiency of vitamin A is rare in theUS, but common in countries where malnourishment is widespread. As mentioned earlier, vitamin A is important to the immune system and vision. This is because the body uses vitamin A to make various internal tissues, such as those lining the eye, lungs, and intestinal tract. When these linings are weakened by vitamin A deficiency, it is easier for harmful bacteria to penetrate them and thus, people with vitamin A deficiency are more prone to infections, illness, blindness, and respiratory problems.
Aside from the malnourished, other people who may be prone to vitamin A deficiency include those who consume large amounts of alcohol and those with certain metabolic disorders that affect how fat and other nutrients are absorbed by the body.
Some recent and ongoing studies involving vitamin A and beta carotene include investigations as to whether high amounts of vitamin A contribute to osteoporosis, and whether beta carotene can lower the risk of some forms of cancer.
As of this writing the Recommended Daily Intake for Vitamin A was 2,310 IU for females and 3,000 IU for males. For a current list of recommendations and list of foods that contain Vitamin A from the National Institutes for Health visit http://ods.od.nih.gov/factsheets/vitamina/
In light of the obesity epidemic of recent decades, it is clear our sugar intake has increased drastically, including our intake of artificial sweeteners. There are many who believe that artificial sweeteners are the solution to our obesity epidemic, but are they really a lesser evil? Did you know that aspartame was initially developed as a medical treatment for stomach ulcers?
 This means your tabletop sweetener or that can of diet coke you’ve just consumed was originally intended to be a prescription drug. Aspartame and saccharine are the most common artificial sweeteners encountered on a daily basis, and they can usually be found in your breakfast cereal, diet sodas, tabletop sweeteners and more. While they may well be low in calories, what is the price you pay for the alternative? Medical studies have indicated a possible connection between aspartame and migraines
, and headaches
. Sucralose, an active compound in many commercial sweeteners on the market, has also recently been found to trigger migraines
. Depression can also manifest from the consumption of artificial sweeteners. Regular dosages of aspartame have been found to decrease serotonin levels, which is the main cause of depression in the brains of mice
. Individuals suffering from mood disorders, such as bipolar disorder, are advised against the regular consumption of artificial sweeteners, since they are more sensitive to the adverse effects of aspartame
. There have been numerous studies and discussions about the carcinogenic properties of artificial sweeteners.
Whether aspartame or saccharine causes cancer is the subject of much debate, with numerous studies yielding inconclusive results. One Argentinean study  cites aspartame usage as the main cause of urinary tract tumors. Others suggest the FDA re-evaluate their position on the safety of aspartame in light of recent studies on animals, linking cancer risks to artificial sweetener consumption . Additional health risks may be caused by the consumption of artificial sweeteners. One possibility is that the long-term intake of aspartame may impair the liver’s antioxidant status and could lead to liver injury . Those suffering from fibromyalgia should also be cautious with their aspartame intake, since it may induce a curable but chronic pain . Many switch over to artificial sweeteners for weight loss purposes. However it may be the sweeteners themselves that contribute to obesity. With the rise of the obesity epidemic correlating with the use of artificial sweeteners, studies have been conducted to ascertain whether there is a link. Some theories postulate that sweeteners such as aspartame induce hunger cravings, causing us eat more and therefore gain weight, but results thus far have been contradictory and inconclusive .
 R.G. Bianchi, E.T. Muir, D.L. Cook, E.F. Nutting, J Environ Pathol Toxicol. 1980 Jun-Jul;3(5-6):355-62.  R.B. Lipton, L.C. Newman, J.S. Cohen & S. Solomon, Headache. 1989  S.K. Van den Eeden et al, Neurology. 1994 Oct;44(10):1787-93.  M.E. Bigal & A.V. Krymchantowski, Headache. 2006 Mar;46(3):515-7.  R.P. Sharma & R.A. Coulombe Jr., Food Chem Toxicol. 1987 Aug;25(8):565-8.  R.G. Walton, R. Hudak & R.J. Green-Waite, Biol Psychiatry. 1993 Jul 1-15;34(1-2):13-7.  M.M. Andreatta, S.E. Muñoz, M.J. Lantieri, A.R. Eynard, A. Navarro, Prev Med. 2008 Jul;47(1):136-9. Epub 2008 Apr 8  J. Huff & J. LaDou, Int J Occup Environ Health. 2007 Oct-Dec;13(4):446-8.  M. Abhilash, M.V. Paul, M.V. Varghese, R.H. Nair, Clin Exp Rheumatol. 2010 Nov-Dec;28(6 Suppl 63):S131-3. Epub 2010 Dec 22.  R. Ciappuccini et al., Clin Exp Rheumatol. 2010 Nov-Dec;28(6 Suppl 63):S131-3. Epub 2010 Dec 22.  F. Bellisie & A. Drewnowski, Eur J Clin Nutr. 2007 Jun;61(6):691-700. Epub 2007 Feb 7.
Vitamin D is one of the few vitamins our body needs that it can produce independently of our diet. This fat-soluble vitamin is unique in humans because it functions as a prohormone, a precursor to the ordinary hormone, and is synthesized when our skin is exposed to the sun. It is synthesized in the kidneys in the form of calcitriol, before it is released into the body as a hormone. It regulates the concentration of calcium and phosphate in the blood stream, helping to promote healthy growth and remodeling in our bones. The regular intake or production of Vitamin D in our bodies can help to prevent rickets in children and the onset of osteomalacia in adults. Vitamin D, especially when combined with calcium, helps to maintain healthy bones and can also reduce the risk of osteoporosis later in life. While it is commonly known that Vitamin D is good for the health of our bones, many people do not know that it also affects the function of the neuromuscular and immune systems, inflammation and cell growth . Vitamin D also partly modulates the genes in the body that regulate cell proliferation, differentiation and apoptosis
. The recommended dietary intake, recommended by the Food and Nutrition board at the Institute of Medicine of the National Academies, is about 15-20mcg in a healthy adult for optimal bone and overall health
. Even though getting regular sunlight is the simplest way to top up Vitamin D levels, many people don’t get sufficient sun, particularly if they live in a colder climate or during the winter. Fortunately there are plenty of food sources out there that can help support our Vitamin D intake. In some countries, it is not uncommon to come across food that has been artificially fortified with Vitamin D
. But the regular consumption of fatty fish, such as catfish, salmon, mackerel, sardines, eel and tuna, can help to naturally get enough Vitamin D in our diet. Other food sources are also rich in Vitamin D, such as: whole eggs, beef liver, fish liver oils – including cod liver oil, mushrooms and yeast that have been grown under UV light. It is important to maintain a healthy balanced diet rich in Vitamin D and to get enough sunlight when the weather is nice enough to do so. Vitamin D is important for a healthy skeletal system, immune system , may reduce the risk against cancer  and may even reduce the overall mortality risks from any cause .
References:  Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.  Holick MF. Vitamin D. In: Shils ME, Shike M, Ross AC, Caballero B, Cousins RJ, eds. Modern Nutrition in Health and Disease, 10th ed. Philadelphia: Lippincott Williams & Wilkins, 2006.  Norman AW, Henry HH. Vitamin D. In: Bowman BA, Russell RM, eds. Present Knowledge in Nutrition, 9th ed. Washington DC: ILSI Press, 2006.  DRI, Dietary reference intakes: for calcium, phosphorus, magnesium, vitamin D, and fluoride. Washington, D.C: National Academy Press. 1997. p. 250. ISBN 0-309-06350-7. Nutrition  http://web.archive.org/web/20080419071840/http://www.sciencenews.org/articles/20061111/bob9.asp Accessed October 2011  Ingraham, BA; Bragdon, B; Nohe, A (January 2008). “Molecular basis of the potential of vitamin D to prevent cancer”. Current Medical Research and Opinion 24 (1): 139–49.  Autier P, Gandini S. Vitamin D supplementation and total mortality: a meta-analysis of randomized controlled trials. Arch Intern Med 2007;167:1730-7.  Giovannucci E. Can vitamin D reduce total mortality? Arch Intern Med 2007;167:1709-10.