Vitamin D in cancer treatment

The way to get the active form of vitamin D is to get outdoors, especially when the sun shines. In winter, however, there's not enough UVB for our body to produce sufficient amounts of vitamin D. 

Vitamin D supplementation

• In the elderly, the skin produces 4-times less vitamin D when exposed to the sun, as compared to younger people. 
• Vitamin D maintenance:  during the summer months, just getting outside for an hour a day should provide sufficient Vitamin D (you'll get most of your Vitamin D if you go outside between 10 AM to 2 PM). I'd supplement Vit. D during autumn and winter (> 2000IU/day, depending on your age and diet).
• Magnesium is essential for proper Vitamin D function. I suggest taking a good magnesium supplement daily, 200 to 400mg suffices. (magnesium malate, magnesium bisglycinate, magnesium chloride).
• Other co-factors: K2, Zinc, and Boron.
• Good sources of vitamin D from food: sardines, tuna, egg yolks, and mushrooms.
• High-dose treatment for advanced cancer could be beneficial {study The high-dose vitamin D group initially took 8,000 IU a day for 14 days, then 4,000 IU a day thereafter}. Anecdotal evidence points to possible incremental benefits with (much) higher doses.
• CD44 downregulation {ref}
• CYP24A1 inhibition facilitates the anti-tumor effect of vitamin D3 on many types of cancer cells. CYP24A1 has been shown to be highly expressed in numerous cancers, including esophageal, cervical, breast, lung, thyroid, and colon cancers, as compared with surrounding normal tissues. Supplementation with carnosic acid-rich rosemary extract was associated with a significant decrease in CYP24A1 {ref} Of note, CYP24A1 Expression Inversely Correlates with Melanoma Progression.
• Caution: Correlation of Vitamin D3, Insulin-Like Growth Factor 1 and Insulin Resistance in Pre-Diabetes and Newly Diagnosed Type 2 Diabetes {ref}
• Vitamin D is also involved in the pathways of production of Melatonin 🛈.

The bioavailability of Vitamin D depends on Magnesium (mg)

Leafy green vegetables, whole grains, beans, nuts, and fish are the best ways to keep healthy levels of magnesium in your body

Role of Magnesium in Vitamin D Activation and Function Anne Marie Uwitonze, BDT, MS; Mohammed S. Razzaque, MBBS, PhD

Vitamins B2 and D3 interaction

https://www.ncbi.nlm.nih.gov/pubmed/24618756
https://www.tarladalal.com/recipes-for-Foods-Rich-in-Vitamin-B2-Riboflavin-1114

⚡ Vitamin D and Beta-Glucans Synergically Stimulate Human Macrophage Activity

⮏ Antagonistic interaction between vitamin D and vitamin A

Taking Vitamin A above the Recommended Daily Allowance  has been found to reduce the effects of vitamin D.  Vitamin A protects against vitamin D toxicity in part by helping to properly regulate the production of vitamin K-dependent proteins. People who take high doses of Vitamin D should not only increase Magnesium but also Vitamin A.

image source

Vitamin D3 supplementation in early-stage prostate cancer

Vitamin D calculator

This is a useful tool to help you calculate how much Vitamin D to supplement. It's recommended to first test your vitamin D blood levels. A healthy Vitamin D range is 21 to 45 ng/ml. (probably best closest to 45 ng/ml)

Vitamin D Calculator

How Much Sunlight Is Equivalent to Vitamin D Supplementation?

"At noon in Miami, someone with Fitzpatrick skin type III would require 6 minutes to synthesize 1000 IU of vitamin D in the summer and 15 minutes in the winter. Someone with skin type V would need 15 and 29 minutes, respectively. At noon in the summer in Boston, necessary exposure times approximate those in Miami, but in winter, it would take about 1 hour for type III skin and 2 hours for type V skin to synthesize 1000 IU of D. After 2 PM in the winter in Boston, it is impossible for even someone with Fitzpatrick type I skin to receive enough sun to equal even 400 IU of vitamin D"
(Craig A. Elmets, MD reviewing Terushkin V et al. J Am Acad Dermatol 2010 Jun Tsiaras WG and Weinstock MA. J Am Acad Dermatol 2010 Jun)

Translating Controlled Experiments into Reality for Human Sun Exposure Times

Vitamin D CONVERSION

https://unitslab.com/node/84

Calcitriol Suppresses HIF-1 and HIF-2 Transcriptional Activity by Reducing HIF-1/2α Protein Levels via a VDR-Independent Mechanism {ref}

References & Sources

• Vitamin D and Gastric Cancer: A Ray of Sunshine? {ref}
• 1α,25(OH)2D3 reverses exhaustion and enhances antitumor immunity of human cytotoxic T cells {study}
• High-dose vitamin D shows benefit in patients with advanced colorectal cancer
• Natural Ways to Increase Calcitriol and Vitamin D Receptor Gene Expression {article}
• Why seniors are more vulnerable to calcium and vitamin D deficiency
• https://www.ilifelink.com/vitamin_ds_anti-cancer_protection_found_to_include_lymphomas.html
• Vitamin D dials down the aggression in melanoma cells
• https://www.lesswrong.com/posts/c5aycbSsSc38XWPEc/taking-vitamin-d3-with-k2-in-the-morning
• Flu The possible roles of solar ultraviolet-B radiation and vitamin D in reducing case-fatality rates from the 1918–1919 influenza pandemic in the United States
• https://www.sciencealert.com/midday-shade-boosts-vitamin-d
• 📙Embrace the Sun by Marc B. Sorenson, William B Grant
• https://www.nature.com/articles/s12276-018-0038-9/figures/1
• Effects of Niacin and Vitamin D on Endothelial Cell Angiogenic Function and Vascular Regeneration During Lipotoxicity
• The dynamic relationships between the active and catabolic vitamin D metabolites, their ratios, and associations with PTH {ref}
• Vitamin D: Metabolism, Molecular Mechanism of Action, and Pleiotropic Effects DOI 10.1152/physrev.00014.2015 Sylvia Christakos, Puneet Dhawan, Annemieke Verstuyf, Lieve Verlinden, Geert Carmeliet
• Sunlight, Nutrition, and Health Research Center
• Vitamin D receptor(s): In the nucleus but also at membranes? {study}