Sun exposure is the most important natural source of vitamin D. The body uses the vitamin to absorb the calcium it needs to build and maintain bones. Short bursts of sun exposure can usually allow your body to produce all the vitamin D it needs for the day.
Some people, including older people or those with kidney or liver problems, may be at risk of becoming deficient in vitamin D. They can consider eating more foods that contain vitamin D or taking a supplement. When exposing the skin to the sun, it is essential to consider the risk of skin cancer. People should avoid allowing their skin to burn.
New research examines whether genetic predisposition to high vitamin D levels affects overall health and mortality risk. What are some of the best omega-3 supplements? Learn about the possible benefits of these supplements and what to look for when buying them. The best vitamin brands are transparent about their testing and quality control practices. Here, find 14 of these brands and learn about what they….
Reanalyzing data from a s trial suggests that the amount of daily vitamin C needed for good health may be much higher than some experts currently….
Calcium and vitamin D work together to keep the bones strong. Separately, they also contribute to the health of the skin, blood, and brain. How to get more vitamin D from the sun. Medically reviewed by Stacy Sampson, D. Tips for getting vitamin D from the sun. Share on Pinterest The sun provides a reliable source of vitamin D.
How do you get vitamin D from the sun? What factors prevent you from getting vitamin D from the sun? Share on Pinterest Vitamin D deficiency is a possible risk for older people.
Holick copyright , reproduced with permission from. The UVB lamps and residents in a day room of a nursing home. This was also supported by the fact that hours of sun exposure was directly related to circulating concentrations of 25 OH D Fig. B Seasonal fluctuation of serum 25 OH D according to frequency of sun exposure. Mean circulating hydroxyvitamin D levels in children, adolescents, and adults according to geographic latitude.
However another study reported that those living at the highest latitudes in Europe at higher circulating concentrations of 25 OH D Fig.
Relationship between the serum 25OHD concentration and northern latitude in Europe. The likely explanation is that some people living far North and South of the equator who could not make any significant amount of vitamin D 3 in their skin for more than half of the year Fig.
People have a feeling of wellbeing when exposed to sunlight. This led to the use of solariums as a way to treat patients with tuberculosis and gave rise to the use of heliotherapy to improve health. One of the first association studies relating sun exposure with reduced risk for cancer was reported in by Hoffman, 74 who found that living at a higher latitude was associated with an increased risk for mortality from cancer.
He compared cancer mortality between and and observed that cancer mortality increased with increasing distance from the equator Fig. Mortality from cancer in cities according to latitude, — Four years later, Apperly 76 compared total cancer mortality in the populations studied with the percentage of Americans and Canadians in the same population who were engaged in agriculture.
He concluded that cancer mortality was highest in farmers living in the Northeast compared with those living in the South Fig. He concluded that the fact that these Southern farmers had nonmelanoma skin cancer resulted in them developing an immunity to the skin cancer which also resulted in an immunity to all cancers including those with high mortality rate.
Showing the relation of total cancer mortality rates to Smith's Solar Radiation Index in the American states, white population only. These observations essentially went unnoticed and the curious relationship of increased sun exposure and living at a lower latitude reducing risk of cancer mortality was buried in the literature. Forty years would pass before Garland et al. United States, — These results together suggested that living at higher latitudes meant less exposure to vitamin D producing sunlight and therefore the connection with the first association with latitude and cancer mortality could be linked to an inverse relationship with cancer mortality and vitamin D status.
A Latitude vs. B Latitude vs. A multitude of epidemiologic studies followed these initial observations not only in the United States and Canada but worldwide.
Grant 79 reported a dramatic inverse relationship between premature mortality due to cancer with UV exposure in both men and women Fig. In the United States, inverse associations with exposure to solar UVB radiation and cancer risk and mortality were reported for ovarian 80 and breast cancer, 81 cancers of the digestive system 79 , 82 and prostate cancer.
Giovannucci et al. Luscombe et al. It was also reported that adults who developed lymphoma had a decreased risk for mortality if they had more sun exposure as a teenager. Also women over 40 y who had the most sun exposure lost the benefit since their risk was no different than those who had the least sun exposure.
B Premature mortality due to cancer, white females, vs. Relative risk of cancer incidence and mortality related to solar UV-B exposure, northern vs. Covariables included in the Cox proportional hazards model: age, height, smoking history, and intakes of total calories, alcohol, red meat, calcium, retinol, and total fruits and vegetables.
Kaplan-Meier plot showing association of UVR exposure and age at diagnosis with prostate cancer. The observational and epidemiologic studies relating increased latitude with increased risk for cancers suggest a possible role of sun induced vitamin D 3 synthesis as the beneficial factor responsible for these observations. Effect of cholecalciferol on rate of rise of PSA.
Median and quartiles of rate of PSA increase prior to starting cholecalciferol visits —4 to —2 and visits —2 to 0 and after starting cholecalciferol visits 0 onward. Lappe et al. The Women's Health Initiative WHI initially reported that women who took mg of calcium and IUs of vitamin D 3 daily for up to 8 y had no reduced risk for colorectal cancer.
Kaplan-Meier survival curves i. Copyright Robert P. Heaney, Cod liver oil was used in the mids to treat tuberculosis. Hope-Simpson had speculated that there was a seasonal stimulus responsible for reducing infectious diseases during the summer.
It is known for example that influenza infection is most prevalent in the winter months at latitudes North and South of the equator but is sporadic throughout the year in children and adults who live near the equator Fig.
It has been hypothesized that the seasonal variation could be due to a seasonal variation in circulating levels of 25 OH D.
The seasonal and latitudinal distribution of outbreaks of type A influenza in the world, —, summarized from the Weekly Epidemiological Record of the World Health Organization into major zones. The diagrams show for each calendar month the percentage of each zone's total outbreaks. In both north and south temperate zones the epidemics are distributed around the local midwinter, whereas the tropical zones show a transition, each approximating toward the distribution of its own temperate zone.
Macrophages play an important role in fighting infectious diseases by ingesting and then destroying them. This is one of the mechanisms believed to be responsible for vitamin D reducing risk of infectious diseases. Liu et al. This was substantiated by Adams et al.
Once 1,25 OH 2 D completes the task of maintaining normal cellular proliferation and differentiation, it induces the hydroxyvitamin Dhydroxylase OHase. Thus, the local production of 1,25 OH 2 D does not enter the circulation and has no influence on calcium metabolism. There are a variety of association studies demonstrating that being born or living near the equator reduces risk of several autoimmune diseases.
Prevalence of multiple sclerosis MS by latitude in the United States according to data from Noonan et al. The dashed line is a quadratic fit to the data from Noonan et al. A plot of the incidence of type 1 diabetes vs. Children younger than 14 y during — in 51 regions worldwide demonstrated a 10—15 fold increase in risk for developing type 1 diabetes if they were born in far Northern and Southern latitudes Fig. Data points are shown by dots; names shown adjacent to the dots denote location, where space allows.
Where space was limited, numerical codes below designate location. Numerical codes for areas: 2. Beja, Tunisia; 3. Gafsa, Tunisia; 4. Kairoan, Tunisia; 5. Monastir, Tunisia; 7. Mauritius; 8. Wuhan, China; 9. Sichuan, China; Huhehot, China; Nanjing, China; Jinan, China; Harbin, China; Changsha, China; Hainan, China; Hong Kong, China; Israel; Chiba, Japan; Hokkaido, Japan; Okinawa, Japan; Novosibirsk, Russia; Antwerp, Belgium; Varna, Bulgaria; Denmark; France; Baden, Germany; Attica, Greece; Sicily, Italy; Pavia, Italy; Marche, Italy; Lazio, Italy; Krakow, Poland; Algarve, Portugal; Coimbra, Portugal; Madeira Island, Portugal; Portalegre, Portugal; Bucharest, Romania; Slovakia; Catalonia, Spain; Leicestershire, UK; Northern Ireland, UK; Avellaneda, Argentina; Corrientes, Argentina; Paraguay; Lima, Peru; Caracas, Venezuela; Auckland, New Zealand.
Data points not labeled because of space constraints latitude in degrees, rate per , : Dalian, China 39, 1. Guilin, China 24, 0. Beijing, China 40, 0. Shanghai, China Chang Chun, China 44, 0. Jilin, China 43, 0. Shenyang, China 42, 0. Lanzhou, China 36, 0. Nanning, China 23, 0. Zhengzhou, China 35, 0. Tie Ling, China 42, 0. Zunyi, China 28, 0. Wulumuqi, China 44, 0. Karachi, Pakistan 25, 0. Austria 48, 9. Hungary 47, 8. Turin, Italy 45, Lombardia, Italy 46, 7.
Slovenia 46, 6. It was also reported that spring births were associated with increased likelihood of developing type 1 diabetes. These findings indicate a potential role of vitamin D in the pathogenesis of type 1 diabetes mellitus. Interestingly as a result of this decrease in vitamin D intake there is an impressive increase in the incidence of type 1 diabetes occurring in Finland over the past 3 decades Fig. Incidence rate of type 1 diabetes diagnosed at or before 14 y of age in Finland.
A pronounced North-South gradient has also been reported for i nflammatory bowel disease, in particular Crohn's disease Fig.
Variation in inflammatory bowel disease incidence rates with degrees latitude from the equator. Merlino et al. This figure illustrates the geographic variation in rheumatoid arthritis risk and shows a clear North-South gradient. Odds ratios are relative to the whole study area.
A Adjusted, optimal span of 0. B Adjusted, span of 0. Small span size results in more spatial variation in risk. Results for addresses at time of censoring. Although the exact mechanisms by which vitamin D may reduce risk for autoimmune diseases are not fully understood we do know that vitamin D plays an important role in cellular immunity.
Thus by doing so it may reduce production of autoantibodies responsible for causing autoimmune diseases. Bouillon et al. Overview of the pharmacological effects of 1,25 OH 2 D in the immune system. Together, these immunomodulatory effects of 1,25 OH 2 D onto players of the adaptive immune system can lead to the protection of target tissues in autoimmune diseases and transplantation.
In the innate immune system on the other hand, 1,25 OH 2 D strengthens the antimicrobial function of monocytes and macrophages, for example through enhanced expression of the CAMP, eventually leading to better clearance of pathogenic microorganisms. In Rostand et al. This was followed by the observation of Krause et al. A control group was exposed to the same UV lamps that were covered by an acrylic shield absorbing all UVB radiation and thus was exposed to UVA radiation only.
These data suggested that vitamin D may somehow be involved in cardiovascular health. One of the first insights as to how vitamin D could influence cardiovascular health was the observation that 1,25 OH 2 D 3 suppressed the production of renin.
A Relationship of mean systolic blood pressure SBP and distance north or south of the equator. B Relationship of mean diastolic blood pressure DBP to distance north or south of the equator. Relationship of prevalence of hypertension to distance north or south of the equator. Effect of UV irradiation on ambulatory daytime and night-time blood pressures was non-significant. Thick line represents the mean. Two major contributing factors for cardiovascular disease are type 2 diabetes and obesity.
Several epidemiologic studies and prospective studies have reported a highly significant association with vitamin D deficiency with not only type 2 diabetes but also hypertension, hyperlipidemia and peripheral vascular disease all causative factors for coronary artery disease, myocardial infarction, heart failure and stroke.
This could explain why vitamin D deficiency is associated with an increased overall and cardiovascular mortality in patients with metabolic syndrome Fig. Macrophages stained with Oil Red O. A Diabetic subjects group A. Top, 1,25 OH 2 D 3 -treated cells; bottom, vitamin D—deficient cells. Arrowheads indicate foam cells. C Oil Red O stain. D Cholesterol. Kaplan-Meier plots for all-cause left and cardiovascular mortality right according to 25 OH D groups in those with the metabolic syndrome.
Schizophrenia has been associated with inadequate sun exposure and vitamin D deficiency Fig. Association between latitude and schizophrenia prevalence on several continents. Vitamin D could play an indirect role in the pathogenesis of schizophrenia. Several studies suggest that a prenatal influenza exposure increases the risk for schizophrenia later in life.
There are a variety of association studies relating vitamin D deficiency with increased risk for depression, , Alzheimer disease, epilepsy, and neurocognitive decline. They recommended that to satisfy Recommendations of the Institute of Medicine and the Endocrine Society Practice Guidelines for daily vitamin D supplementation to prevent vitamin D deficiency.
They also found that most but not all of the literature supports the concept that vitamin D 2 is as effective as vitamin D 3 in maintaining circulating concentrations of 25 OH D. For almost y a variety of strategies have been used to treat and prevent vitamin D deficiency especially in children. Russian children who are being exposed to UVB radiation. The Sperti lamp which originally was designed with a single mercury arc lamp , was commonly used in the United States in the s and s to prevent rickets and children Fig.
Photograph of a current version of the Sperti lamp with four fluorescent lamps. Exposure to a tanning bed emitting UVB radiation was effective in improving her circulating concentration of 25 OH D and as a result markedly improved her bone discomfort Fig.
Furthermore an evaluation of their bone mineral density revealed that the tanners had a significantly higher bone mineral density in their hip compared with the control group.
Sensible sun exposure can also be an excellent source of vitamin D for both children and adults. Comparison of the percentage increase in serum 25 OH D levels of healthy adults who were in a bathing suit and exposed to suberythemal doses 0. Skin type is based on the Fitzpatrick scale: Type II always burns, sometimes tans; type III always burns, always tans; type IV sometimes burns, always tans; type V never burns, always tans.
Because foods contain very little vitamin D it is difficult to obtain enough vitamin D from dietary sources even when consuming foods fortified with vitamin D. Infants should receive IUs of vitamin D soon after they are born. The best method to treat and cure rickets is to give a total dose of 5—15 mg ,—, IUs of vitamin D 2 or vitamin D 3 orally with adequate dietary calcium.
Children one year and older should receive at least IUs of vitamin D daily. The Endocrine Society recommends at least IUs and up to IUs daily is safe and effective to prevent vitamin D deficiency and insufficiency. The total 25 OH D levels are demonstrated over time. Because vitamin D is fat soluble upon its ingestion or production in the skin vitamin D 3 gets incorporated into the body fat and is also transported to the liver to be converted to 25 OH D. Patients on glucocorticoids, anti-seizure medications and AIDS medications may also need more vitamin D to both treat and prevent vitamin D deficiency.
This can also occur in patients with some lymphomas. Mean serum hydroxyvitamin D 25[OH]D and calcium levels. Results are given as mean SEM values averaged over 6-mo intervals.
Time 0 is initiation of treatment. Forty-one of the patients were vitamin D insufficient or deficient and first received 50 IU ergocalciferol weekly for 8 weeks before being placed on maintenance therapy of 50 IU of ergocalciferol every 2 weeks.
To convert 25 OH D to nanomoles per liter, multiply by 2. B Mean serum 25 OH D levels in patients receiving maintenance therapy only.
C Serum calcium levels. Results for all 86 patients who were treated with 50 IU of ergocalciferol vitamin D 2. The reference range for serum calcium level is 8. Vitamin D intoxication is one of the rarest medical conditions and is often caused by inadvertent or intentional ingestion of extremely high doses of vitamin D for prolonged periods of time.
Vitamin D intoxication is associated with hypercalcemia, hyperphosphatemia, suppression of PTH that can lead to nephrocalcinosis and soft tissue calcification especially of blood vessels. No matter how much sun exposure a person has this will never cause vitamin D intoxication because sunlight itself destroys any excess vitamin D and previtamin D.
Often simply removing all sources of vitamin D along with hydration can result in the serum calcium returning to normal within a relatively short period of time and with no sequelae. Our ancestors routinely worshiped the sun for its life giving properties Fig. Females born with vitamin D deficiency and suffering from infantile rickets resulted in them having a flat pelvis and a small pelvic outlet. These females although fertile would have had a difficult time, if not impossible, to give vaginal birth resulting in both maternal and fetal death.
Egyptian painting showing the pharao and the queen being exposed to sunshine. It is remarkable that for more than y investigators have been reporting an inverse association with latitude and many chronic illnesses including common cancers, 85 several autoimmune diseases including type 1 diabetes and multiple sclerosis 73 , - as well as hypertension.
The global appreciation of the beneficial effects of vitamin D for health lead to widespread vitamin D fortification throughout Europe and the United States in the ss. Not only milk but hot dogs, soda, custard, bread, cereals and even beer was fortified with vitamin D Fig.
Unfortunately in the early s the outbreak of hypercalcemia in British infants, who also had birth defects which included altered facial features, mental retardation, and heart problems, was incorrectly attributed to be over fortification of milk with vitamin D since it was believed that these were signs of vitamin D intoxication.
This legislation was quickly adopted in most European countries and was used as a reason by other countries not to fortify milk with vitamin D. Clearly the paranoia about food fortification with vitamin D causing toxicity needs to be reconsidered in light of observations that infants who consumed IU vitamin D per day during their first year of life not only did not have any evidence of toxicity but for the ensuing 31 y markedly decreased their risk for type 1 diabetes.
In the s sunscreens were first introduced as a way to prevent sunburning. The sunscreens contained UVB absorbing chemicals such as paraaminobezoic acid because it was believed that only UVB radiation damaged the skin and caused skin cancer. It is now realized that UVA radiation not only alters the immune system making it more immunotolerant but also increases risk for non-melanoma and melanoma skin cancers. Over the past four decades with very little thought as to its consequences, several national and international health organizations have condemned any direct sun exposure.
The American Academy of Dermatology has taken the extreme position of recommending that no one should ever be exposed to direct sunlight without sun protection. This radical view of sunlight and UVB radiation has led to its designation as a carcinogen.
The lack of appreciation of the importance of sensible sun exposure for providing children and adults with their vitamin D requirement has led to a worldwide vitamin D deficiency pandemic. The CDC concluded that vitamin D deficiency is becoming more prevalent in the US because of obesity, decrease in the consumption of vitamin D fortified milk and increased sun protection.
Sensible sun exposure which is free, eating foods that naturally contain vitamin D or are fortified with vitamin D as well as taking a vitamin D supplement should guarantee vitamin D sufficiency. There is no downside to increasing vitamin D intake and there could be a substantial upside, i. A Schematic representation of the major causes for vitamin D deficiency and potential health consequences.
Previously published online: www. National Center for Biotechnology Information , U. Journal List Dermatoendocrinol v. Published online Jan 1. Matthias Wacker and Michael F. Author information Article notes Copyright and License information Disclaimer. Holick, Email: ude. Received Mar 15; Accepted Mar The article may be redistributed, reproduced, and reused for non-commercial purposes, provided the original source is properly cited.
This article has been cited by other articles in PMC. Abstract Vitamin D is the sunshine vitamin that has been produced on this earth for more than million years. Prehistoric Perspective Life forms began to evolve in the oceans over 1 billion years ago. Open in a separate window. Historical Perspective As the industrial revolution swept across Northern Europe in the s resulting in buildings built in close proximity and coal burning causing a pall of air pollution Fig. Photochemistry of Provitamin D 3 During exposure to sunlight solar radiation with wavelengths of — nm penetrate into the skin and are absorbed by proteins, DNA and RNA as well as 7-dehydrocholesterol.
Sun Controlled Cutaneous Production of Vitamin D 3 During exposure to sunlight after previtamin D 3 is produced it will absorb solar UVB radiation and isomerize into two major photoproducts, lumisterol 3 and tachysterol 3 Fig.
Skin Pigment Humans evolved at the equator. Aging It was observed that 7-dehydrocholesterol concentrations in human epidermis were inversely related to age Fig. Sunlight and Non-Calcemic Health Benefits Historical perspective People have a feeling of wellbeing when exposed to sunlight. Sunlight and Vitamin D: The Cancer Connection One of the first association studies relating sun exposure with reduced risk for cancer was reported in by Hoffman, 74 who found that living at a higher latitude was associated with an increased risk for mortality from cancer.
Sunlight and Vitamin D: Autoimmunity Protection There are a variety of association studies demonstrating that being born or living near the equator reduces risk of several autoimmune diseases. Concern about Vitamin D Intoxication Vitamin D intoxication is one of the rarest medical conditions and is often caused by inadvertent or intentional ingestion of extremely high doses of vitamin D for prolonged periods of time.
Conclusion and Perspective Our ancestors routinely worshiped the sun for its life giving properties Fig. Disclosure of Potential Conflicts of Interest No potential conflicts of interest were disclosed. Footnotes Previously published online: www. References 1. Holick M. Phylogenetic and evolutionary aspects of vitamin D from phytoplankton to humans. Holick MF. Vitamin D: A millenium perspective. J Cell Biochem. Ergosterol content in various fungal species and biocontaminated building materials.
Appl Environ Microbiol. Generation of potentially bioactive ergosterol-derived products following pulsed ultraviolet light exposure of mushrooms Agaricus bisporus Food Chem.
Vitamin D and skin physiology: a D-lightful story. J Bone Miner Res. Evolutionary importance for the membrane enhancement of the production of vitamin D 3 in the skin of poikilothermic animals. Kinetic and thermodynamic studies of the conversion of previtamin D 3 to vitamin D 3 in human skin. J Biol Chem. Resurrection of vitamin D deficiency and rickets. J Clin Invest. Brennemann J, McQuarrie I. Brennemann's practice of pediatrics: W. Prior; Palm TA. The geographical distribution and etiology of rickets.
Huldschinsky K. Dtsch Med Wochenschr. The ultra-violet light treatment of rickets. The cure of infantile rickets by sunlight. J Am Med Assoc. Steenbock H, Black A. The reduction of growth-promoting and calcifying properties in a ration by exposure to ultraviolet light. Hess AF, Weinstock M. Antirachitic properties imparted to inert fluids and to green vegetables by ultra-violet irradiation. Vitamin D: the underappreciated D-lightful hormone that is important for skeletal and cellular health.
Curr Opin Endocrinol Diabetes Obes. You and Your Hormones. Students Teachers Patients Browse. Human body. Home Hormones Vitamin D. Vitamin D Vitamin D is a hormone produced by the kidneys that helps to control the concentration of calcium in the blood and is vital for the development of strong bones. Alternative names for vitamin D Calcitriol or 1,dihydroxyvitamin D ; ergocalciferol vitamin D 2 ; cholecalciferol vitamin D 3 ; calcidiol hydroxyvitamin D What is vitamin D?
How is vitamin D controlled? What happens if I have too little vitamin D? What happens if I have too much vitamin D? Last reviewed: Feb Prev. Related Endocrine Conditions. Related Hormones.
0コメント