I don't see any reason to pester her on Twitter, but wanted to comment on this:
https://twitter.com/ashleyfmiller/statu ... 9982439425
Link is to FB:
Ashley Miller wrote:Just saw my skin in the midday sun for the first time in a while. Vitamin d deficiency was come by honestly. There is no color in any of my skin, wrist or leg is the same as forearm or shoulder. Yeesh, I've always been pale, but this is new.
By "skin color" she's referring to "no tan" as a proxy for "little to no exposure to UV radiation". Her natural skin color being pale makes it (a) far
easier for her to make adequate vitamin D from minimal UVA exposure, and (b) less likely
a priori that she's vitamin D deficient, as compared with someone with more melanin.
One so moved might even call this "vitamin D synthesis privilege". :?
Bolding in the abstracts below was added by me:
2013 medical journal article
Skin color is relevant to vitamin D synthesis
BACKGROUND: Whether dark skin produces less vitamin D after UVB radiation than fair skin remains controversial.
OBJECTIVE: To compare 25-hydroxyvitamin D [25-(OH)-D] levels after a single UVB exposure in fair (phototype II-III) and black-skinned (phototype VI) volunteers.
METHODS: Fair-skinned volunteers (n = 20, 4 males/16 females, mean age: 23.2 years) and black-skinned (n = 11, 6 males/5 females, mean age: 23.8 years) received a single total body UVB exposure (0.022 J/cm(2)). The 25-(OH)-D levels were measured on days 0, 2 and 6.
RESULTS: On day 0, all volunteers were severely vitamin D deficient. On day 2, 25-(OH)-D levels of fair-skinned volunteers increased significantly (median: 11.9-13.3 ng/ml, p < 0.0001), but not in black-skinned people (median: 8.60-8.55 ng/ml, p = 0.843). Again, on day 6, 25-(OH)-D levels of fair-skinned volunteers increased significantly (median: 11.9-14.3 ng/ml, p < 0.0001), but not in black-skinned people (median: 8.60-9.57 ng/ml, p = 0.375).
CONCLUSION: This study suggests that skin pigmentation negatively influences vitamin D synthesis.
2/2015 medical journal article
Vitamin D deficiency in minority populations
OBJECTIVE: Black and Hispanic individuals synthesize less vitamin D per unit of sun exposure than white individuals. The relationship between UV radiation and vitamin D insufficiency in minorities has not been well explored.
DESIGN: Prospective cohort study.
SETTING: Using the National Health and Nutrition Examination Survey, we obtained serum vitamin D levels for non-Hispanic Whites, Hispanics and non-Hispanic Blacks aged ≥18 years from 2000-2006. We linked these data with the average monthly solar UV index by census tract and data on sun exposure, vitamin D supplementation, health and demographics. We used multivariable regression analyses to assess vitamin D deficiency (<15 ng/ml) and insufficiency (<20 ng/ml) in January (when the UV index was lowest) by race/ethnicity and geography.
SUBJECTS: Adults (n 14,319) aged ≥18 years.
RESULTS: A 1-point increase in the UV index was associated with a 0·51 ng/ml increase in vitamin D (95% CI 0·35, 0·67 ng/ml; P<0·001). Non-Hispanic Black race and Hispanic ethnicity were associated with a 7·47 and 3·41 ng/ml decrease in vitamin D, respectively (both P<0·001). In January, an estimated 65·4% of non-Hispanic Blacks were deficient in vitamin D, compared with 28·9% of Hispanics and 14·0% of non-Hispanic Whites. An estimated 84·2% of non-Hispanic Blacks were insufficient in vitamin D v. 56·3% of Hispanics and 34·8% of non-Hispanic Whites. More non-Hispanic Blacks were estimated to be deficient in vitamin D in January in the highest UV index quartile than were non-Hispanic Whites in the lowest UV index quartile (60·2% v. 25·7%).
CONCLUSIONS: Wintertime vitamin D insufficiency is pervasive among minority populations, and not uncommon among non-Hispanic Whites.