Portobello Mushrooms

Our portobello mushrooms are not regular portobello you can find at the supermarket. Incredibly, someone thought to expose mushrooms to the sun to see if they would produce vitamin D and low and behold they did! These mushrooms are specially grown and contain Vitamin D2, which is made by plants. Research has shown that vitamin D2 is as effective on humans as vitamin D3, which comes from animal sources and is made by human skin when exposed to sunlight.

Vitamin D is known as the “sunshine vitamin.” That’s because our bodies convert sunlight into the vitamin. But in fact, it’s technically not a vitamin at all; it’s a hormone that our body produces. It was inaccurately dubbed a “vitamin” in the 1920s and the label has stuck.

Regardless of its name, vitamin D is an important factor in the maintenance of good health. It helps in the development and maintenance of good bones and teeth, aids in the absorption and use of phosphorus. It is also essential for the absorption of calcium, which, when combined with sufficient Vitamin D, a healthy diet and regular exercise may reduce the risk of developing osteoporosis.

As one medical review suggested, “adequate vitamin D status seems to be protective against musculoskeletal disorders, infectious diseases, autoimmune diseases, cardiovascular disease, type 1 and type 2 diabetes mellitus, several types of cancer, neurocognitive dysfunction and mental illness, and other diseases, as well as infertility and adverse pregnancy and birth outcomes.”

The problem is that it’s been suggested three-quarters of US teens and adults are lacking the vitamin and that more than 50% of women and men ages 65 and older are vitamin D-deficient.

The cause is partly linked to increased use of sunscreen to protect against harmful UV rays, and environmental concerns such as cloud cover and pollution are a factor, but for many proximity is to blame. If you live north of the 37th parallel – which is anywhere north of San Francisco, CA on the west and Richmond, VA to the east, including all of Canada – it’s simply impossible to get enough vitamin D. Even if someone lives in peak-sun southern regions, our modern lifestyle of desk jobs and indoor work limits our ability to produce vitamin D.

Since vitamin D is actually a hormone, it’s essentially impossible to get through food – at least from organic food sources or in manageable quantities. Vitamin D in supplements is virtually all animal based and derived from sheep wool lanolin – that’s the oil of the skin of sheep. While this might sound fine to some, it just didn’t sit right with us. Products that are enriched with vitamin D such as milk also for the most part contain this form of Vitamin D as an additive.

Other research suggests that inadequate levels of vitamin D can be a risk factor for breast cancer. As Harvard Health wrote, “At a scientific meeting in May 2008, Canadian researchers reported that vitamin D deficiency was linked to poorer outcomes in women.” In fact, in one study of 90 women with breast cancer and 90 without, it was found that “invariably almost all patients with breast cancer were vitamin D deficient.” One reason may be that “vitamin D may play a role in controlling normal breast cell growth and may be able to stop breast cancer cells from growing.”

Active constituents
Protocatcechuic acid, pyrocatechol, phosphorus and potassium, conjugated linoleum acid


Vitamin D2 and its efficacy in humans as compared to vitamin D3

The researchers in this study determined whether vitamin D2 was less effective than vitamin D3 in maintaining serum 25-hydroxyvitamin D levels or increased the destructive metabolism of 25-hydroxyvitamin D3. Through a randomized, placebo-controlled, double-blinded study, healthy adults ages 18 to 84 years old received a placebo, 1000 IU vitamin D3, 1000 IU vitamin D2, or 500 IU vitamin D2 plus 500 IU vitamin D3 daily for 11 weeks at the end of the winter. The study concluded that a 1000 IU dose of vitamin D2 daily was as effective as 1000 IU vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not negatively influence serum 25-hydroxyvitamin D3 levels. Therefore, vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status.

Holick, Michael F., et al. "Vitamin D2 is as effective as vitamin D3 in maintaining circulating concentrations of 25-hydroxyvitamin D." The Journal of Clinical Endocrinology & Metabolism 93.3 (2008): 677-681.

The purpose of this study was to determine 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and 1,25-dihydroxyvitamin D2 [1,25(OH)2D2] levels in 34 healthy adults consuming 1000 IU vitamin D2 or vitamin D3. The research demonstrates that supplementation with 1000 IU of Vitamin D2 or D3 resulted in similar increases in respective serum 25(OH)D concentrations and did not alter serum concentrations of 1,25(OH)2 D3 or total 1,25(OH)2 D.

Biancuzzo, Rachael M et al. “Serum concentrations of 1,25-dihydroxyvitamin D2 and 1,25-dihydroxyvitamin D3 in response to vitamin D2 and vitamin D3 supplementation.” The Journal of clinical endocrinology and metabolism vol. 98,3 (2013): 973-9. doi:10.1210/jc.2012-2114

The researchers in this study recruited 40 healthy men and women into a double-blind, parallel design, randomized controlled trial. Participants received placebo or 1 of 4 experimental treatments (D2 or D3 at 5 or 10 μg/d) supplied as a malted milk drink during a period of minimal UV-B exposure in the UK. The results showed that both D2- and D3-fortified drinks resulted in dose-dependent increases (P < 0.001) in their respective 25-OH metabolites that did not significantly differ in size. These findings suggest that D2 and D3 are equipotent in increasing 25-OH-D in healthy men and women with negligible UV-B exposure.

Fisk, Catherine M., Hannah E. Theobald, and Thomas AB Sanders. "Fortified malted milk drinks containing low-dose ergocalciferol and cholecalciferol do not differ in their capacity to raise serum 25-hydroxyvitamin D concentrations in healthy men and women not exposed to UV-B." The Journal of nutrition 142.7 (2012): 1286-1290.

The objective of this study was to compare increases in plasma 25-hydroxyvitamin D [25(OH)D] concentrations and attainment of 50 and 75 mol/L status cutoffs following 3 months of daily supplementation with D2 compared with D3 in healthy, breastfed, 1-month-old infants. The findings suggest that the increase in the 25(OH)D concentration among the D2 and D3 groups did not differ, suggesting daily intake of either isoform is acceptable for infants less than 4 months.

Gallo, Sina et al. “The change in plasma 25-hydroxyvitamin D did not differ between breast-fed infants that received a daily supplement of ergocalciferol or cholecalciferol for 3 months.” The Journal of nutrition vol. 143,2 (2013): 148-53. doi:10.3945/jn.112.167858

Comparison of mushroom-derived D2 to traditional D3 supplements

This study compared the bioavailability of vitamin D2 in mushrooms with the bioavailability of vitamin D2 or vitamin D3 in a supplement. It revealed that ingestion of 2000 IUs of vitamin D2 in mushrooms is as effective in raising and maintaining blood levels of 25-hydroxyvitamin D,  which is a marker for a person's vitamin D status, as ingesting 2000 IUs of vitamin D2 or vitamin D3 in a supplement. Therefore, the research suggests that mushrooms are a rich source of vitamin D2 that, when consumed, can increase and maintain vitamin D levels in a healthy range. Ingestion of mushrooms may also provide the consumer with a source of vitamin D3 and vitamin D4.

Keegan, Raphael-John H et al. “Photobiology of vitamin D in mushrooms and its bioavailability in humans.” Dermato-endocrinology vol. 5,1 (2013): 165-76. doi:10.4161/derm.23321

Few foods contain vitamin D2 (ergocalciferol) or vitamin D3 (cholecalciferol). Treatment of mushrooms with UV light increases ergocalciferol content and could provide a dietary source of vitamin D. This study of 38 healthy adults sought to determine if consuming one serving of cooked, UV-treated mushrooms per day for 6 weeks would increase vitamin D2 levels and improve vitamin D status (assessed by measuring total 25(OH)D) in healthy adults. Two levels of UV-treated mushrooms were compared to ergocalciferol from capsules and to untreated mushrooms.

Stephensen, Charles B., et al. "Ergocalciferol from mushrooms or supplements consumed with a standard meal increases 25-hydroxyergocalciferol but decreases 25-hydroxycholecalciferol in the serum of healthy adults." The Journal of nutrition 142.7 (2012): 1246-1252.

Vitamin D and it’s impact on general health

In this review, the authors combined data on randomized controlled trials, meta-analyses, and other evidence of vitamin D action on various health outcomes. The review suggests adequate vitamin D status seems to be protective against musculoskeletal disorders (muscle weakness, falls, fractures), infectious diseases, autoimmune diseases, cardiovascular disease, type 1 and type 2 diabetes mellitus, several types of cancer, neurocognitive dysfunction and mental illness, and other diseases, as well as infertility and adverse pregnancy and birth outcomes. Vitamin D deficiency/insufficiency is associated with all-cause mortality.

Pludowski, Pawel, et al. "Vitamin D effects on musculoskeletal health, immunity, autoimmunity, cardiovascular disease, cancer, fertility, pregnancy, dementia and mortality—a review of recent evidence." Autoimmunity reviews 12.10 (2013): 976-989.

This review explores the epigenetic mechanisms of vitamin D that could help explain many of the non-skeletal benefits of enhancing vitamin D status. The authors suggest that there is no downside to increasing vitamin D intake, and recent observations suggesting that vitamin D influences epigenetics provide a new insight for the importance of vitamin D in utero in reducing risk of chronic diseases later in life.

Hossein-nezhad, Arash, and Michael F. Holick. "Optimize dietary intake of vitamin D: an epigenetic perspective." Current Opinion in Clinical Nutrition & Metabolic Care 15.6 (2012): 567-579.

In this review, the relation between vitamin D and 137 outcomes has been explored, covering a wide range of skeletal, malignant, cardiovascular, autoimmune, infectious, metabolic, and other diseases. On the basis of the available evidence, an association between vitamin D concentrations and birth weight, dental caries in children, maternal vitamin D concentrations at term, and parathyroid hormone concentrations in patients with chronic kidney disease requiring dialysis is probable.

Theodoratou, Evropi et al. “Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomised trials.” BMJ (Clinical research ed.) vol. 348 g2035. 1 Apr. 2014, doi:10.1136/bmj.g2035

The researchers in this study conducted a systematic search of prospective and intervention studies that assessed the effect of 25(OH)D concentrations on non-skeletal health outcomes in individuals aged 18 years or older. The discrepancy between observational and intervention studies suggests that low 25(OH)D is a marker of ill health. Inflammatory processes involved in disease occurrence and clinical course would reduce 25(OH)D, which would explain why low vitamin D status is reported in a wide range of disorders. In elderly people, restoration of vitamin D deficits due to ageing and lifestyle changes induced by ill health could explain why low-dose supplementation leads to slight gains in survival.

Autier, Philippe, et al. "Vitamin D status and ill health: a systematic review." The lancet Diabetes & endocrinology 2.1 (2014): 76-89.

This review outlines the beneficial effects of Vitamin D on human health by demonstrating the role of vitamin D as a global regulator of homeostasis, and also focuses on current views and its relevance to human physiology and pathology.

Wierzbicka, Justyna, Anna Piotrowska, and Michał A. Żmijewski. "The renaissance of vitamin D." Acta Biochimica Polonica 61.4 (2014).

The goal of this work was to estimate the reduction in mortality rates for six geopolitical regions of the world under the assumption that serum 25-hydroxyvitamin D (25(OH)D) levels increase from 54 to 110 nmol/l. The researchers conclude that increasing serum 25(OH)D levels is the most cost-effective way to reduce global mortality rates, as the cost of vitamin D is very low and there are few adverse effects from oral intake and/or frequent moderate UVB irradiance with sufficient body surface area exposed.

Grant, W. B. "An estimate of the global reduction in mortality rates through doubling vitamin D levels." European journal of clinical nutrition 65.9 (2011): 1016-1026.

Vitamin D and it’s impact on development of healthy bones and teeth

The aim of this study was to investigate the association of serum 25-hydroxyvitamin D (25-OHD) concentration with current physical performance (mineralization defects, bone loss, and muscle weakness) and its decline among 1,234 elderly men and women. The results found that serum 25-OHD concentrations below 20 ng/ml are associated with poorer physical performance and a greater decline in physical performance in older men and women.

Wicherts, Ilse S., et al. "Vitamin D status predicts physical performance and its decline in older persons." The Journal of Clinical Endocrinology & Metabolism 92.6 (2007): 2058-2065.

The aim of this observational study was to examine the relationship between serum levels of 25-hydroxyvitamin D (25OHD) and fracture risk in a cohort of 1662 men. The results revealed a relationship between baseline 25OHD and fracture risk was U-shaped, with increased fracture risk in men with either low or high serum 25OHD levels. Thus the research suggests that men with mean vitamin D serum levels (25OHD ≥60 to ≤72 nmol/L) had the least risk of fracture.

Bleicher, Kerrin, et al. "U‐shaped association between serum 25‐hydroxyvitamin D and fracture risk in older men: results from the prospective population‐based CHAMP study." Journal of Bone and Mineral Research 29.9 (2014): 2024-2031.

In this study, researchers evaluated the association between a predictor score of plasma 25-hydroxyvitamin D (25(OH)D) and incidence of periodontitis and tooth loss, observed in 13,581 incidents. The results suggest an association between predictors of vitamin D and lower incidence of tooth loss and periodontitis.

Jimenez, Monik et al. “Predicted vitamin D status and incidence of tooth loss and periodontitis.” Public health nutrition vol. 17,4 (2014): 844-52. doi:10.1017/S1368980013000177

This study aimed to analyze the relationship between serum 25-hydroxy-vitamin D (25(OH)D) status and dental health data obtained from 1,048 children. The research concludes that elevated serum 25(OH)D concentrations were associated with better dental health parameters.

Kühnisch, J et al. “Elevated serum 25(OH)-vitamin D levels are negatively correlated with molar-incisor hypomineralization.” Journal of dental research vol. 94,2 (2015): 381-7. doi:10.1177/0022034514561657

Vitamin D and it’s impact on osteoporosis

In this review, the author reports on the relationships between vitamin D and osteoporotic fracture risk. Then, they present the data from the literature regarding the effects of vitamin D on risk factors such as fall risk and reduction in BMD, physical performance, and cognitive performance. The research supports evidence of a relationship between low concentration of serum 25-hydroxyvitamin D and low cognitive abilities, which have been shown to be a risk factor for falling.

Marcelli, C., C. Chavoix, and P. Dargent-Molina. "Beneficial effects of vitamin D on falls and fractures: is cognition rather than bone or muscle behind these benefits?." Osteoporosis international 26.1 (2015): 1-10.

The researchers determined whether calcium supplementation can reduce osteoporotic fractures by conducting a meta-analysis to include all the randomised trials in which calcium, or calcium in combination with vitamin D, was used to prevent fracture and osteoporotic bone loss. The evidence supports the use of calcium, or calcium in combination with vitamin D supplementation, in the preventive treatment of osteoporosis in people aged 50 years or older.

Tang, Benjamin MP, et al. "Use of calcium or calcium in combination with vitamin D supplementation to prevent fractures and bone loss in people aged 50 years and older: a meta-analysis." The Lancet 370.9588 (2007): 657-666.

This report describes the effect of vitamin D supplementation on repletion to 25(OH)D levels ≥50 nmol/L in 371 postmenopausal women with osteoporosis. The results found that supplementation with daily median doses of 2000 IU vitamin D successfully repleted 88% of postmenopausal women with osteoporosis within 48 days to a serum vitamin D level of 50 nmol/L.

Chung, Yoon Sok et al. “Vitamin D Repletion in Korean Postmenopausal Women with Osteoporosis.” Yonsei medical journal vol. 57,4 (2016): 923-7. doi:10.3349/ymj.2016.57.4.923

The present study examined whether modified oak mushrooms could improve or prevent osteoporosis-like symptoms in mice fed with low calcium and vitamin D3-deficient diet. The results indicate that in mice, vitamin D2 and/or calcium derived from irradiated oak mushrooms may improve bone mineralization through a direct effect on the bone, and by inducing the expression of calcium-absorbing genes in the duodenum and kidney.

Lee, Geun-Shik, et al. "Dietary calcium and vitamin D 2 supplementation with enhanced Lentinula edodes improves osteoporosis-like symptoms and induces duodenal and renal active calcium transport gene expression in mice." European journal of nutrition 48.2 (2009): 75.


There is ongoing research on the effects of Vitamin D as it relates to the following health concerns:

Vitamin D and it’s impact on breast cancer

In this work, the researchers conducted a systematic review and meta-analysis of the association of vitamin D with breast cancer outcomes among breast cancer patients. They identified eight studies reporting the associations of blood vitamin D levels (drawn close to diagnosis) with breast cancer outcomes in 5,691 patients. These findings support an association of low levels of vitamin D with increased risk of recurrence and death in early stage breast cancer patients.

Rose, April AN, et al. "Blood levels of vitamin D and early stage breast cancer prognosis: a systematic review and meta-analysis." Breast cancer research and treatment 141.3 (2013): 331-339.

The aim of this study was to determine serum vitamin D levels in 90 breast cancer patients and an equal number of age-matched healthy females, to assess its risk association with grade and stage of the tumor. The research suggests almost all patients with breast cancer were vitamin D deficient. In addition, tumor characteristics did not show any significant associations with serum levels of vitamin D, and bone mineral density did not correlate significantly with vitamin D deficiency.

Imtiaz, Saba et al. “Vitamin D deficiency in newly diagnosed breast cancer patients.” Indian journal of endocrinology and metabolism vol. 16,3 (2012): 409-13. doi:10.4103/2230-8210.95684

This study was conducted by measuring Vitamin D levels in 512 women with early breast cancer. Clinical, pathologic, and dietary data were accessed to examine prognostic effects of vitamin D. The results showed that Vitamin D deficiency may be associated with poor outcomes in breast cancer.

Cescon, David W., et al. "Feasibility of a randomized controlled trial of vitamin D vs. placebo in women with recently diagnosed breast cancer." Breast cancer research and treatment 134.2 (2012): 759-767.

In this literature review, the authors examine five studies that assess the association of serum 25(OH)D levels with survival in colorectal and breast cancer patients. The studies suggest that higher 25(OH)D levels (>75nmol/L) were associated with significantly reduced mortality in patients with colorectal and breast cancer.

Maalmi, Haifa, et al. "Serum 25-hydroxyvitamin D levels and survival in colorectal and breast cancer patients: systematic review and meta-analysis of prospective cohort studies." European journal of cancer 50.8 (2014): 1510-1521.

The objective of this report was to describe and examine serum concentrations of 25-hydroxyvitamin D [25(OH)D] in 790 breast cancer survivors. The results showed that in these breast cancer survivors, the prevalence of vitamin D insufficiency was high, suggesting clinicians might consider monitoring vitamin D status in breast cancer patients, together with appropriate treatments, if necessary.

Neuhouser, Marian L et al. “Vitamin D insufficiency in a multiethnic cohort of breast cancer survivors.” The American journal of clinical nutrition vol. 88,1 (2008): 133-9. doi:10.1093/ajcn/88.1.133

The goal of this work was to perform a meta-analysis of 25 published studies to assess the associations of circulating 25(OH)D levels measured at or near the time of diagnosis and outcomes for cancer patients.The results indicate that cancer patients with higher circulating 25(OH)D levels at or near the time of diagnosis have better outcomes.

Li, Mian, et al. "the impacts of circulating 25-hydroxyvitamin D levels on cancer patient outcomes: a systematic review and meta-analysis." The Journal of Clinical Endocrinology & Metabolism 99.7 (2014): 2327-2336.

Vitamin D and it’s impact on mental health

The researchers in this study aimed to determine if there was a relationship between vitamin D concentrations and individuals with or without common mental disorders (CMDs), by evaluating the extent to which the association between 25(OH)D and CMDs are explained by these behaviours. This study provides support for an association of low 25(OH)D concentrations with current and subsequent risk of depression in mid-adulthood.

Maddock, Jane, et al. "Vitamin D and common mental disorders in mid-life: cross-sectional and prospective findings." Clinical nutrition 32.5 (2013): 758-764.

The aim of the present randomized, double-blind, placebo control trial, was to investigate if vitamin D supplementation had an effect on vitamin D status, executive functioning and self-perceived mental health in a group of 50 adolescents during winter time. Multivariate data analysis showed that participants with low vitamin D status scored worse on cognitive tests and more difficult subtasks. They also had a tendency to report higher frequency of externalizing behavior problems and attention deficit. Overall, the study indicates that vitamin D status in adolescents may be important for both executive functioning and mental health.

Grung, Bjørn, et al. "Linking vitamin D status, executive functioning and self‐perceived mental health in adolescents through multivariate analysis: A randomized double‐blind placebo control trial." Scandinavian journal of psychology 58.2 (2017): 123-130.

In this work, researchers analyzed one case-control study, 10 cross-sectional studies and three cohort studies with a total of 31,424 participants. The researchers concluded that their analyses were consistent with the hypothesis that low vitamin D concentration is associated with depression.

Anglin, Rebecca ES, et al. "Vitamin D deficiency and depression in adults: systematic review and meta-analysis." The British journal of psychiatry 202.2 (2013): 100-107.

The researchers performed this study to evaluate whether low maternal vitamin D levels are associated with depressive symptoms in pregnancy. The result of the research showed that in women at risk for depression, early pregnancy low vitamin D levels are associated with higher depressive symptom scores in early and late pregnancy.

Williams, Jennifer Anne et al. “Vitamin D levels and perinatal depressive symptoms in women at risk: a secondary analysis of the mothers, omega-3, and mental health study.” BMC pregnancy and childbirth vol. 16,1 203. 3 Aug. 2016, doi:10.1186/s12884-016-0988-7

Vitamin D and it’s impact on other health concerns

Colorectal Cancer

A meta-analysis was performed of studies of the relationship between 25(OH)D and mortality of patients with colorectal cancer. The results demonstrate that higher serum 25(OH)D was associated with lower mortality of patients with colorectal cancer. These results suggest that colorectal cancer patients with deficient levels of serum 25(OH)D should have their levels restored to a normal range (30-80ng/ml).

Mohr, Sharif B., et al. "Could vitamin D sufficiency improve the survival of colorectal cancer patients?." The Journal of steroid biochemistry and molecular biology 148 (2015): 239-244.

In this study, the researchers directly measured serum 25OHD levels at surgery and examined the association with survival among 257 patients with colorectal cancer. The result suggest that higher 25OHD levels at surgery may be associated with a better survival rate of patients with colorectal cancer.

Mezawa, Hidetoshi et al. “Serum vitamin D levels and survival of patients with colorectal cancer: post-hoc analysis of a prospective cohort study.” BMC cancer vol. 10 347. 2 Jul. 2010, doi:10.1186/1471-2407-10-347


The goal of this study was to define the relationship between vitamin D deficiency and fibromyalgia syndrome in 100 women. The researchers found that among the 100 fibromyalgia women, there were 61 women with 25(OH) D deficiency. Thus they concluded that vitamin D deficiency has to be considered in the management of fibromyalgia syndrome.

Matthana, Mona H. “The relation between vitamin D deficiency and fibromyalgia syndrome in women.” Saudi medical journal vol. 32,9 (2011): 925-9.

The present study was designed to determine the association between serum 25-hydroxyvitamin D [25-(OH)D] deficiency and nonspecific skeletal pain in 276 patients diagnosed with leg pain, widespread pain, arthralgia, rib pain, back pain and fibromyalgia. The results of this study indicate a positive association of vitamin D deficiency with a variety of nonspecific bone pain, particularly in women.

Heidari, Behzad, et al. "Association between nonspecific skeletal pain and vitamin D deficiency." International journal of rheumatic diseases 13.4 (2010): 340-346.

The aim of this study was to determine the prevalence of vitamin D deficiency (<20 ng/dl) among 139 patients with fibromyalgia or muscle pain. The results found that 103 (74%) of these patients had a low vitamin D level and that treatment resulted in clinical improvement in 90% of patients. Thus, non-specific muscle pains may indicate vitamin D deficiency, and prompt treatment may result in resolution of symptoms.

Badsha, Humeira, Mirna Daher, and Kok Ooi Kong. "Myalgias or non-specific muscle pain in Arab or Indo-Pakistani patients may indicate vitamin D deficiency." Clinical rheumatology 28.8 (2009): 971-973.


The purpose of this study was to determine the relationship between measured vitamin D levels and both markers of asthma severity and allergy in 616 children with asthma. The results suggest that vitamin D insufficiency is relatively frequent in an equatorial population of children with asthma. In these children, lower vitamin D levels are associated with increased markers of allergy and asthma severity.

Brehm, John M et al. “Serum vitamin D levels and markers of severity of childhood asthma in Costa Rica.” American journal of respiratory and critical care medicine vol. 179,9 (2009): 765-71. doi:10.1164/rccm.200808-1361OC

The researchers in this work systematically reviewed pediatric clinical trials investigating the role of vitamin D on asthma-related respiratory outcomes in five studies. The available evidence from this systematic review suggests that high dose vitamin D may prevent asthma exacerbation.

Pojsupap, Supichaya, et al. "Efficacy of high-dose vitamin D in pediatric asthma: a systematic review and meta-analysis." Journal of Asthma 52.4 (2015): 382-390.

The objective of this paper was to synthesize the evidence from studies that have measured the association between serum vitamin D and asthma incidence, prevalence, severity, and exacerbations through a systematic search of the literature. These results suggest that vitamin D supplementation may be effective for the prevention of asthma exacerbations.

Cassim, R., et al. "The role of circulating 25 hydroxyvitamin D in asthma: a systematic review." Allergy 70.4 (2015): 339-354.

Irritable Bowel Disease

The aim of this review is to critically evaluate several strands of scientific evidence surrounding vitamin D and inflammation, primarily focusing on irritable bowel syndrome. Several strands of evidence suggest that vitamin D may modify the immune response in IBD.

O'Sullivan, Maria. "Vitamin D as a novel therapy in inflammatory bowel disease: new hope or false dawn?." Proceedings of the Nutrition Society 74.1 (2015): 5-12.

This pilot study was performed on 18 patients with mild-to-moderate Crohn's disease to determine the dose of vitamin D needed to raise serum vitamin D levels above 40 ng/ml. The results found that twenty-four weeks supplementation with up to 5,000 IU/d vitamin D3 effectively raised serum 25(OH)D3 and reduced CDAI scores in a small cohort of Crohn's patients suggesting that restoration of normal vitamin D serum levels may be useful in the management of patients with mild-moderate Crohn's disease.

Yang, Linlin et al. “Therapeutic effect of vitamin d supplementation in a pilot study of Crohn's patients.” Clinical and translational gastroenterology vol. 4,4 e33. 18 Apr. 2013, doi:10.1038/ctg.2013.1

Cardiovascular Disease

The present study evaluated the effect of vitamin D insufficiency on epicardial coronary flow rate, subclinical atherosclerosis, and endothelial function of 222 patients who had undergone coronary angiography for suspected ischemic heart disease and were found to have normal or near-normal coronary artery. A strong association was found between vitamin D insufficiency and the SCF phenomenon. In addition, vitamin D insufficiency was associated with endothelial dysfunction and subclinical atherosclerosis.

Oz, Fahrettin, et al. "Impact of vitamin D insufficiency on the epicardial coronary flow velocity and endothelial function." Coronary artery disease 24.5 (2013): 392-397.

Weight Loss

The purpose of this study was to prospectively examine the effect of weight loss on serum 25(OH)D concentration on 383 overweight or obese women. These findings suggest that weight loss, presumably associated with a reduction in body fat, is associated with increased serum 25(OH)D concentration in overweight or obese women.

Rock, Cheryl L et al. “Weight loss is associated with increased serum 25-hydroxyvitamin D in overweight or obese women.” Obesity (Silver Spring, Md.) vol. 20,11 (2012): 2296-301. doi:10.1038/oby.2012.57