Vitamin D tests used in this video
Your personalised vitamins
Single test, £39.99
Year plan, 2 tests and vitamin D supplies to titrate, £75
BetterYou test
£32.95
Vitamin D Test Kit + Free Vitamin D Oral Spray
Vitamin D into the body
D3 (cholecalciferol), sun, animals or supplement
D2 (ergocalciferol), plants, supplements
Pathway
In the skin
Vitamin D, cholecalciferol, synthesised in the skin
In the liver
Converted to its major circulating form, 25-hydroxyvitamin D (25(OH)D)
Calcifediol
In the kidneys
Converted into 1,25-dihydroxyvitamin D3, or calcitriol, the principal active hormonal form of vitamin D
Vitamin D in the blood
25 hydroxy vitamin D
25-hydroxyvitamin D (25OHD)
Calcifediol
Circulating concentration of 25OHD is the accepted biomarker for vitamin D status
https://medlineplus.gov/ency/article/003569.htm
Many experts recommend a level between 20 and 40 ng/mL (50 to 100 nmol/L)
Others recommend a level between 30 and 50 ng/mL (75 to 125 nmol/L)
Some say higher
https://www.hindawi.com/journals/dm/2015/864370/
Serum concentrations, units
Nanograms per milliliter (ng/mL)
(1000 ng = 1 microgram)
Nanomoles per liter (nmol/L)
1 ng/mL is equal to 2.5 nmol/L
Supplements
Micrograms
International units
400 IU = 10 mcg
1,000 IU = 25 mcg
2,000 IU = 50 mcg
4,000 IU = 100 mcg
How much to take in Winter?
https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
Do not take more than 100 micrograms (4,000 IU) of vitamin D a day (11 years to adults)
Children aged 1 to 10 years should not have more than 50 micrograms (2,000 IU) a day.
Infants under 12 months should not have more than 25 micrograms (1,000 IU) a day.
Prostate cancer
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1472821/
Colon cancer
https://www.dana-farber.org/newsroom/news-releases/2019/high-dose-vitamin-d-shows-benefit-in-patients-with-advanced-colorectal-cancer/
Breast cancer
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5802611/
Multiple sclerosis
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5990512/
Heart disease
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851242/
Immunity
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166406/
Autoimmunity
https://ard.bmj.com/content/70/9/1569
Diabetes
https://pubmed.ncbi.nlm.nih.gov/32080077/
Chronic pain and sleep
https://pubmed.ncbi.nlm.nih.gov/22699141/
Depression
https://www.jneuropsychiatry.org/peer-review/depression-and-vitamin-d-deficiency-causality-assessment-and-clinical-practice-implications-12051.html
Cytokine storm
https://www.medrxiv.org/content/10.1101/2020.04.08.20058578v4
COVID
https://www.nhs.uk/conditions/coronavirus-covid-19/people-at-higher-risk/get-vitamin-d-supplements/
Source