Why is "vitamin" D deficiency so common?
This chart shows that 64% of the US population is insufficient or deficient in D, at lower than 40 ng/ml or nanograms/milliliter in the blood.
D Deficiency can have long term outcomes in chronic diseases like cancers, diabetes, and heart disease [1].
Fear of skin cancer has created “photophobia,” a total avoidance of sunlight.
Current sun exposure messaging is driven mainly by dermatologists, however, new skin cancers account for only 5 - 6% of all new cancers, see charts below.
Sunscreen prevents sunburn, not skin cancer, and most broad-spectrum Sun Protective Factor sunscreen over 15 SPF blocks 99% of Ultra-Violet light [2].
Current sun exposure recommendations are developed for light-skinned people (Skin type 1 – 3). This makes people of color (Skin type 4 – 6) more at risk for D deficiency.
In April, 2023 Australia adopted sun exposure recommendations for the entire country (factoring in Skin types,
Latitude, Time of year and Time of day) as a preventative measure to improve the health of the entire population equally [3].
Everyone responds differently to D. Skin type, age, weight, sun exposure, medications, and co-nutrients affect D up-take [1].
During winter, north of 350 latitude (Los Angeles to Raleigh, NC), “vitamin” D cannot be made from sunlight due to the tilt of the Earth, see image - yearly sun exposure over the Earth.
All life on Earth evolved under the sun. When scientists tried to figure out what level of “vitamin” D existed in pre-industrial societies (before 1800 AD) they studied societies in Africa in 2016. These largely nomadic people, outside all day, had a constant D blood level of 45 ng/ml [4].
Recommended levels of “vitamin” D are low in the US, at 20ng/ml, and haven’t been revised for over 100 years. Castor oil was known to prevent rickets in children, see Image 1.
The hormone Cholecalciferol (25 [OH] D) aka “vitamin” D3, was added to the public milk supply.
There are questions about the calculation of the current Institute of Medicine recommended level of supplementation (600 – 800 IUs daily). The IOM level may be off by a factor of 10X [5].
Many doctors and research scientists recommend 40 – 60 ng/ml as protective level against chronic illnesses such as cancers, diabetes, and heart disease. D levels must be tested regularly to see how well supplementation is working [1].
All life on Earth evolved under the sun. When scientists tried to figure out what level of "vitamin" D existed in pre-industrial societies (before 1800 AD) they studied societies in Africa in 2016. These largely agricultural people, outside all day, had a constant D blood level of 45 ng/ml [5]
Other factors contributing to a nationwide D deficiency -
Most people don’t have their D level tested regularly (2X/year) and
Don’t know (including doctors) what a protective level is (40 – 60ng/ml).
Most doctors will Not usually order the test at your request and then
Most health insurance companies decline to pay for it [OoP ~ $80/ea].
References: 1. www.grassrootshealth.net 2.Holick, MF, 2003, The UV Advantage, New York, NY iBooks. 3.Australian Sun Exposure Summit “Balancing the Harms and Benefits of Sun Exposure” 2023. 4. Luxwolda, MF.,et al, Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l. Cambridge University Press, 1/23/12. 5. GrassrootsHealth.net/Veugelers. 5. Image: 1. Rickets www.yogavanahill.com/diseases/rickets
