This is part 4 in a ten part series of posts surrounding the myths about melanin.
In this episode we address the myth claiming melanin reduces vitamin D levels, which seems to be, for the most part, a matter of perception. Does melanin reduce vitamin D levels or do people who have high levels of skin melanin require more sunlight to have proper amounts of vitamin D in latitudes where there is less sunlight?
- This myth appears to begin with a 1934 article entitled PIGMENTATION, SUNLIGHT, AND NUTRITIONAL DISEASE by FREDERICK G. MURRAY. Murray went through a great deal of effort to give the impression melanin, or using his term pigmentation, in skin led to rickets. He describes ergosterol, when irradiated or exposed to sunlight, as metabolizing blood calcium and phosphorus into vitamin D. Then, he lists the three cures for rickets as being sunlight, cod liver oil or mercury vapor lamp ultra violet irradiation. Murray states “It has long been recognized that infants of the colored race in the United States are more predisposed to rickets than are the white babies.” He concludes melanin is the cause. What Murray overlooks, from one of his own sources, is the effect of diet in rickets.
- According to Update in vitamin D. Very few people in the United States do not suffer from Vitamin D deficiency. Based on data extracted from the National Health and Nutrition Examination Survey (NHANES) 90% of the United States population with the highest skin melanin levels suffer from vitamin D insufficiency while nearly three fourths of the melanin challenged population does as well. Melanin can’t be to blame for their Vitamin D deficiency too, can it?
- The 2015 study 24,25-Dihydroxyvitamin D3 and Vitamin D Status of Community-Dwelling Black and White Americans found “Blacks frequently have low total 25D without manifestations of vitamin D deficiency, suggesting that total serum 25D may incorrectly reflect vitamin D status in different racial groups.”
- It has been shown individuals with high levels of skin melanin, “living at latitudes comparable to New England, can generate sufficient vitamin D during normal summer seasons to satisfy year-round VD3 requirements.“
- Does testing for vitamin D levels for people with high skin melanin occur in winter or summer?
- People with high levels of skin melanin have low levels of fragility fractures due to osteoporosis even when living at high latitudes.
- What is the level of solar insolation at which melanogenesis occurs? No one ever mentions this simple fact which would, apparently, have a correlation to the UV Index.
- A 2013 New England Journal of Medicine study notes people who have Vitamin-D deficiency present indications of hyperparathyroidism, hypocalcemia, or low BMD. Since Black people lack those conditions another cause had to be found for their low levels of Vitamin-D. Results found African people have a polymorphism in the Vitamin-D binding gene.
- The 2016 study Free 25-Hydroxyvitamin D: Impact of Vitamin D Binding Protein Assays on Racial-Genotypic Associations which included participants from the US, UK and Gambia found results that contradicted the 2013 study findings but could not explain the lack of rickets or Osteomalacia (soft bones).
- Where is the history of rickets and osteomalacia among enslaved Africans?
- Did rickets and osteomalacia not prevail among enslaved Africans due to their skin melanin levels or calcium deficiency due to poor diet?
- In the 17th century rickets was considered the English disease. Rickets was first discovered among the Greeks. If melanin causes low vitamin D then rickets should not have originated among people with low levels of cutaneous melanin.
- Rickets has been found to be due to low levels of calcium, not Vitamin D. The disease manifested during the 1600s in Europe due to pollution from industrialization obscuring sunlight. Less sunlight led to less Vitamin D. What else could science have gotten wrong? It seems the problem of rickets, which became rare during the 20th century, reemerged at the end of the 20th century. But melanin levels did not magically increase during that time period.
- What changed? Are African people spending too much time indoors?
- End result, take cod-liver oil. It has 340% of the recommended daily allowance of Vitamin D.