Obesity increases Cancer - perhaps due to low vitamin D - many articles

VitaminDWiki observation
Obesity ==> reduces the level of vitamin D avaiable in the blood
Obesity ==> outdoors less ==> decreases vitamin D from the sun
Low vitamin D ==> Increased Cancer

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High BMI in late teens linked to higher risk of 17 different cancers later in life - Nov 2023

TrialSiteNews
Note: These were men who were conscripted by the military, so were not very obese
Associations between BMI in youth and site-specific cancer in men—A cohort study with register linkage
Aron Onerup, Kirsten Mehlig, Agnes af Geijerstam, Elin Ekblom-Bak, Hans-Georg Kuhn, Lauren Lissner, Annika Rosengren, Mats Börjesson, Maria Åberg

Objective
This study examined BMI in young men and incident site-specific cancer to estimate population attributable fractions due to BMI based on projected obesity prevalence.

Methods
A population-based cohort study with measured height and weight at age 18. Cox regression models assessed linear associations for BMI and included age, year, and site of conscription as well as parental level of education as covariates.

Results
Primary analyses were performed in 1,489,115 men, of whom 78,217 subsequently developed cancer during a mean follow-up of 31 years. BMI was linearly associated with risk of developing all 18 site-specific cancers assessed (malignant melanoma; leukemia; myeloma; Hodgkin lymphoma; non-Hodgkin lymphoma; and cancer in the lungs, head and neck, central nervous system, thyroid, esophagus, stomach, pancreas, liver and gallbladder, colon, rectum, kidney, and bladder), in some instances evident at BMI levels usually defined as normal (20–25 kg/m2). Higher BMI was associated with lower risk of prostate cancer. The highest hazard ratios and population attributable fractions were seen for some gastrointestinal cancers.

Conclusions
This study reports linear associations between BMI at age 18 and subsequent site-specific cancers, calling for rapid action to stem the obesity epidemic and to prepare the health care system for steep increases in cancer cases.

Study Importance
What is already known?

• In men, obesity is an established risk factor for cancer in the esophagus, gastric cardia, colon and rectum, liver, gallbladder, pancreas, kidney, and thyroid and for multiple myeloma.
• In contrast, the evidence is weaker in adolescents and young adults, although generally consistent with associations in older adults, according to the International Agency for Research on Cancer.

What does this study add?

• We provide effect sizes for associations between BMI in youth and site-specific cancers from a population-based sample of 1.5 million men and can report linear associations between BMI and leukemia; myeloma; Hodgkin lymphoma; non-Hodgkin lymphoma; and cancer in the lungs, central nervous system, and urinary bladder.
• The uniform age at BMI assessment and the extended follow-up period allowed us to provide projections of attributable fractions accounting for the global obesity epidemic.

 Download the PDF from VitaminDWiki

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Obesity linked to 13 cancers, the linkage is probably vitamin D – Aug 2016

• Obesity linked to 13 cancers, the linkage is probably vitamin D – Aug 2016

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Obesity causes 20 percent of all cancer, low vitamin D may be the connection – meta-analysis - Sept 2014

Obesity and cancer: the role of vitamin D

Forest Plot: Obesity and Vitamin D

Background
It is estimated that 20% of all cancer cases are caused by obesity. Vitamin D is thought to be one of the mechanisms underlying this association. This review aims to summarise the evidence for the mediating effect of vitamin D on the link between obesity and cancer.

Methods
Three literature searches using PubMed and Embase were conducted to assess whether vitamin D plays an important role in the pathway between obesity and cancer: (1) obesity and cancer; (2) obesity and vitamin D; and (3) vitamin D and cancer. A systematic review was performed for (1) and (3), whereas a meta-analysis including random effects analyses was performed for (2).

Results

• (1) 32 meta-analyses on obesity and cancer were identified; the majority reported a positive association between obesity and risk of cancer.
• (2) Our meta-analysis included 12 original studies showing a pooled relative risk of 1.52 (95% CI: 1.33-1.73) for risk of vitamin D deficiency (<50 nmol/L) in obese people (body mass index >30 kg/m2).
• (3) 21 meta-analyses on circulating vitamin D levels and cancer risk were identified with different results for different types of cancer.

Conclusion
There is consistent evidence for a link between obesity and cancer as well as obesity and low vitamin D. However, it seems like the significance of the mediating role of vitamin D in the biological pathways linking obesity and cancer is low. There is a need for a study including all three components while dealing with bias related to dietary supplements and vitamin D receptor polymorphisms.

 Download the PDF from VitaminDWiki.

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Association between obesity and ovarian cancer - Spanish - May 2014

Rev Med Chil. 2014 May;142(5):593-598.
[Article in Spanish]
Valladares M, Corsini G, Romero C.

Obesity is a risk factor for cancer. Epidemiological evidences associate ovarian cancer with obesity. Epithelial ovarian cancer (EOC) is the most common type of ovarian cancer and accounts for a high rate of mortality. The association between ovarian cancer and obesity could be explained by molecular factors secreted by adipose tissue such as leptin. In EOC, leptin increases cell proliferation and inhibits apoptosis. Additionally, adipose tissue synthesizes endogenous estrogens, which increase cell proliferation of epithelial ovarian cells. Also, obesity associated hyperinsulinism could increase ovarian estrogen secretion.

http://revmedchile.org/flips/Revista-Medica-de-Chile-Mayo-2014/#/52/Full article in Spanish is online

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Obesity increases risk of cancer - perhaps vitamin D - Aug 2010

Obesity and increased risk of cancer: does decrease of serum 25-hydroxyvitamin D level with increasing body mass index explain some of the association?
Mol Nutr Food Res. 2010 Aug;54(8):1127-33. doi: 10.1002/mnfr.200900512.
Lagunova Z1, Porojnicu AC, Grant WB, Bruland Ø, Moan JE.
1Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway. zoya.lagunova at rr-research.no

Low levels of vitamin D and excess body weight are both factors associated with increased risk of cancer. The increased risk seems to be proportional to the increase in BMI, and to decrease in serum 25-hydroxyvitamin D (25(OH)D) level. Our earlier investigations suggest that serum 25(OH)D levels decrease with increasing BMI. Although the connection between cancer risk, BMI and vitamin D status might be arbitrary, it has not been discussed in the literature so far. In this study, we analyze data published in current meta-analysis, prospective studies, and systematic reviews on cancer-specific risk attributed to high BMI and low vitamin D status. The contribution of low 25(OH)D levels associated with high BMI to increased cancer risk was calculated for 13 vitamin-D-sensitive cancers with a focus on colorectal and breast cancer as the most frequently studied vitamin-D-sensitive cancer types.
Our study suggests that a low vitamin D status may explain at least 20% of the cancer risk attributable to high BMI.
The contribution of low 25(OH)D to the increased cancer risk with increasing BMI may be different for different cancer types.
Thus, we find 40% for breast cancer, and 26% and 75% for colorectal cancer in men and women, respectively.
PMID: 20512788
Publisher charges $6 to rent the PDF

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BMI associated with 3.6% of new Cancer - Lancet 2014 (not mention vitamin D)

Global burden of cancer attributable to high body-mass index in 2012: a population-based study

The Lancet Oncology, Early Online Publication, 26 Nov 2014, doi:10.1016/S1470-2045(14)71123-4
Dr Melina Arnold PhD a arnoldm at fellows.iarc.fr, Nirmala Pandeya PhD d †, Graham Byrnes PhD b, Prof Andrew G Renehan PhD e, Gretchen A Stevens DSc f, Prof Majid Ezzati FMedSci g, Jacques Ferlay MSc a, J Jaime Miranda PhD h, Isabelle Romieu PhD c, Rajesh Dikshit PhD i, David Forman PhD a, Isabelle Soerjomataram PhD a

Background: High body-mass index (BMI; defined as 25 kg/m2 or greater) is associated with increased risk of cancer. To inform public health policy and future research, we estimated the global burden of cancer attributable to high BMI in 2012.

Methods: In this population-based study, we derived population attributable fractions (PAFs) using relative risks and BMI estimates in adults by age, sex, and country. Assuming a 10-year lag-period between high BMI and cancer occurrence, we calculated PAFs using BMI estimates from 2002 and used GLOBOCAN2012 data to estimate numbers of new cancer cases attributable to high BMI. We also calculated the proportion of cancers that were potentially avoidable had populations maintained their mean BMIs recorded in 1982. We did secondary analyses to test the model and to estimate the effects of hormone replacement therapy (HRT) use and smoking.

Findings: Worldwide, we estimate that 481 000 or 3·6% of all new cancer cases in adults (aged 30 years and older after the 10-year lag period) in 2012 were attributable to high BMI. PAFs were greater in women than in men (5·4% vs 1·9%). The burden of attributable cases was higher in countries with very high and high human development indices (HDIs; PAF 5·3% and 4·8%, respectively) than in those with moderate (1·6%) and low HDIs (1·0%). Corpus uteri, postmenopausal breast, and colon cancers accounted for 63·6% of cancers attributable to high BMI. A quarter (about 118 000) of the cancer cases related to high BMI in 2012 could be attributed to the increase in BMI since 1982.

Interpretation: These findings emphasise the need for a global effort to abate the increasing numbers of people with high BMI. Assuming that the association between high BMI and cancer is causal, the continuation of current patterns of population weight gain will lead to continuing increases in the future burden of cancer.

Funding: World Cancer Research Fund International, European Commission (Marie Curie Intra-European Fellowship), Australian National Health and Medical Research Council, and US National Institutes of Health.

Publisher charges $31.50 for the PDF

Study was summarized in Science Daily

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BMI and Cancer Aug 2014 Lancet (not mention low vitamin D)

Overweight and obesity linked to 10 common cancers, over 12,000 cases every year in UK Science Daily on a different Lancet Study] – Aug 2014
A higher body mass index (BMI) increases the risk of developing 10 of the most common cancers, the largest study of its kind on BMI and cancer, involving more than 5 million adults in the UK, shows. Each 5 kg/m² increase in BMI was clearly linked with higher risk of cancers of the uterus (62% increase), gallbladder (31%), kidney (25%), cervix (10%), thyroid (9%), and leukemia (9%). Higher BMI also increased the overall risk of liver, colon, ovarian, and breast cancer

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See also VitaminDWiki

• Overview Cancer and vitamin D
• Overview Obesity and Vitamin D contains the following summary
• FACT: People who are obese have less vitamin D in their blood
• FACT: Obese need a higher dose of vitamin D to get to the same level of vit D
• FACT: When obese people lose weight the vitamin D level in their blood increases
• FACT: Adding Calcium, perhaps in the form of fortified milk, often reduces weight
• FACT: 168 trials for vitamin D intervention of obesity as of Dec 2021
• FACT: Less weight gain by senior women with > 30 ng of vitamin D
• FACT: Dieters lost additional 5 lbs if vitamin D supplementation got them above 32 ng - RCT
• FACT: Obese lost 3X more weight by adding $10 of Vitamin D
• FACT: Those with darker skins were more likely to be obese Sept 2014
• OBSERVATION: Low Vitamin D while pregnancy ==> more obese child and adult
• OBSERVATION: Many mammals had evolved to add fat and vitamin D in the autumn
  • and lose both in the Spring - unfortunately humans have forgotten to lose the fat in the Spring
• SPECULATION: Low vitamin D might be one of the causes of obesity – several studies
• SUGGESTION: Probably need more than 4,000 IU to lose weight if very low on vitamin D due to
    risk factors such as overweight, age, dark skin, live far from equator,shut-in, etc.
• Obesity category has 442 items

See also: Weight loss and Vitamin D - many studies   Child Obesity and Vitamin D - many studies   Obesity, Virus, and Vitamin D - many studies
Obese need more Vitamin D

• Normal weight     Obese     (50 ng = 125 nanomole)

Click here for 2014 study

Obesity category listing with associated searches has the following clickable graphic
Obese need 2 - 3 X more vitamin D

Vitamin D and Cancer Treatment and Prevention – presentations May 2011 has BMI-Low vitamin D connection charts

Diseases that may be related via low vitamin D which has the following chart

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9+ VitaminDWiki Obesity pages with CANCER in the title

This list is automatically updated

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It appears that Vitamin D restricts new capillary growth (angiogenesis) in fat and cancers