Ultraviolet Exposure and Vitamin D Synthesis in a Sun‐Dwelling and a Shade‐Dwelling Species of Anolis: Are There Adaptations for Lower Ultraviolet B and Dietary Vitamin D3 Availability in the Shade?

2005 ◽  
Vol 78 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Gary W. Ferguson ◽  
William H. Gehrmann ◽  
Kristopher B. Karsten ◽  
Allan J. Landwer ◽  
Elliott N. Carman ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Ultraviolet B ◽  
Dietary Vitamin ◽  
Ultraviolet Exposure

scholarly journals Dietary Intake of Vitamin D from Dairy Products Reduces the Risk of Osteoporosis

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1743 ◽  
Author(s):  
Valeria Polzonetti ◽  
Stefania Pucciarelli ◽  
Silvia Vincenzetti ◽  
Paolo Polidori
Keyword(s):  
Vitamin D ◽  
Older People ◽  
Dietary Intake ◽  
Vitamin D3 ◽  
Calcium Absorption ◽  
Daily Intake ◽  
Winter Season ◽  
The United States ◽  
Ultraviolet B ◽  
Dietary Vitamin

Background: Vitamin D and calcium are important dietary compounds that affect bone mass, even if other minerals (potassium, zinc, etc.) and vitamins (A, C and K) are also involved. Vitamin D and certain minerals, in fact, play an important role in calcium homeostasis and calcium absorption. Hip fracture incidence is higher in Europe and the United States, where calcium is frequently included in the human diet; while the occurrence of these fractures is lower in developing countries, where diets are often poor in calcium. This condition is named the “calcium paradox”, and may be partially explained by phosphate toxicity, which can negatively affect mineral metabolism. It is important to maintain correct dietary calcium-phosphate balance in order to have a healthy life, reducing the risk of osteoporotic fractures in older people. Vitamin D can also act as a hormone; vitamin D2 (ergocalciferol) is derived from the UV-B radiation of ergosterol, the natural vitamin D precursor detected in plants, fungi, and invertebrates. Vitamin D3 (cholecalciferol) is synthesized by sunlight exposure from 7-dehydrocholesterol, a precursor of cholesterol that can also act as provitamin D3. Dietary intake of vitamin D3 is essential when the skin is exposed for short periods to ultraviolet B light (UV-B), a category of invisible light rays such as UV-A and UV-C. This can be considered the usual situation in northern latitudes during the winter season, or the typical lifestyle for older people and/or for people with very white delicate skin. The actual recommended daily intake of dietary vitamin D is strictly correlated with age, ranging from 5 μg for infants, children, teenagers, and adults—including pregnant and lactating women—to 15 μg for people over 65 years.

scholarly journals Vitamin D Dietary Intake through Dairy Products to Reduce the Risk of Osteoporosis

2020 ◽  
Author(s):  
Valeria Polzonetti ◽  
Stefania Pucciarelli ◽  
Silvia Vincenzetti ◽  
Paolo Polidori
Keyword(s):  
Vitamin D ◽  
Older People ◽  
Dietary Intake ◽  
Vitamin D3 ◽  
Calcium Absorption ◽  
Mineral Metabolism ◽  
Daily Intake ◽  
Winter Season ◽  
Ultraviolet B ◽  
Dietary Vitamin

Background: Vitamin D and calcium are important dietary compounds that affect bone mass, even if other minerals (potassium, zinc, etc.) and other vitamins (A, C and K) are also involved. Vitamin D and other minerals, in fact, play an important role in calcium homeostasis and calcium absorption. Hip fractures incidence is higher in western countries, where calcium is frequently included in human diet, while the occurrence of these fractures is lower in developing countries, where diets are often poor in calcium. This situation is known as the “calcium paradox”, and may be partially explained considering phosphate toxicity, that can induce a disorder of mineral metabolism. It is important to maintain adequate dietary calcium-phosphate balance in order to perform a healthy life, reducing the risk of osteoporotic fracture in older people. Vitamin D can also act as a hormone; vitamin D2 (ergocalciferol) is derived from the UV-B radiation of ergosterol, the vitamin D precursor naturally found in plants, fungi, and invertebrates. Vitamin D3 (cholecalciferol) is originated by sunlight exposure from 7-dehydrocholesterol, a precursor of cholesterol that can also act as a provitamin D3. Dietary intake of vitamin D3 is very important when skin is exposed for short times to ultraviolet B light (UV-B) one of the three kinds of invisible light rays together with UV-A and UV-C. This can be considered the usual situation in northern latitudes and in winter season, or the typical condition for older people and/or for people with very white delicate skin. Actually, the recommended daily intake of dietary vitamin D is strictly correlated with age, ranging from 5 μg for infants, children, teen-agers and adults, including women during pregnancy and lactation, to 15 μg for people over 65 years.

scholarly journals Tissue Distribution of Cholecalciferol and 25-hydroxycholecalciferol in Normal and Obese Mice Fed Different Levels of Vitamin D (P24-003-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Chan Yoon Park ◽  
Yongho Shin ◽  
Jeong-Han Kim ◽  
Sung Nim Han
Keyword(s):  
Vitamin D ◽  
Adipose Tissue ◽  
Vitamin D3 ◽  
Control Level ◽  
Dietary Vitamin ◽  
Epididymal Adipose Tissue ◽  
Mrna Levels ◽  
Lower Serum ◽  
Vitamin D Intake ◽  
Different Levels

Abstract Objectives Vitamin D deficiency is often observed in obese person. One of the mechanisms suggested is the decreased bioavailability of vitamin D due to its deposition in adipose tissue. We investigated the effects of obesity on vitamin D distribution by measuring 25(OH)D levels in circulation and comparing vitamin D content in liver and adipose tissue from obese and control mice fed different levels of vitamin D. Methods Six-wk-old C57BL/6 mice were fed control or high fat (10 or 45% kcal fat, CON or HFD) diets containing different levels of vitamin D3 (1000, or 25,000 IU/kg of diet, CVd or HVd) for 13 wks. Serum 25-hydroxyvitamin D (25(OH)D) level was determined by radioimmunoassay. Vitamin D3 and 25(OH)D3 levels in the liver and epididymal adipose tissue (AT) were quantified by LC-MS/MS. mRNA levels of liver Cyp2r1 and Cyp27a1 were determined by real-time PCR. Results Overall, serum 25(OH)D levels were significantly higher in the HVd groups compared with CVd groups. There was no difference in serum 25(OH)D levels between CON-CVd and HFD-CVd groups. However, in the vitamin D supplemented groups, HFD-HVd group had significantly lower serum 25(OH)D levels (20% lower) than CON-HVd group. Vitamin D3 levels in the liver and AT were 55 and 100 times higher in the HVd groups (liver and AT: 719 and 318 ng/g tissue) compared with the CVd groups. 25(OH)D3 levels in the liver and AT were also 3.3 and 2.4 times higher in the HVd groups (liver and AT: 33.9 and 18.9 ng/g tissue) than those of the CVd groups. Total amount of vitamin D3 in the liver and AT were significantly higher in the HFD-HVd group (121 and 44% higher) compared with CON-HVd group. However, when mice were fed the control levels of vitamin D, dietary fat levels did not affect the vitamin D3 amount in the liver and AT. Liver Cyp2r1 and Cyp27a1 mRNA levels did not differ among groups. Conclusions When vitamin D intake was at a supplementation level, a significant amount of dietary vitamin D seemed to be stored in the liver and AT; thus excess body adiposity could contribute to lower serum 25(OH)D level. However, at a control level of vitamin D intake, obesity did not affect tissue vitamin D amount and serum 25(OH)D levels. Funding Sources Supported by the grant from the National Research Foundation (NRF) of Korea (NRF-2018R1D1A1B070491) and Research Grant from Research Affairs at Seoul National University.

scholarly journals A Narrative Review of The Role of Foods as Dietary Sources of Vitamin D of Ethnic Minority Populations with Darker Skin: The Underestimated Challenge

Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 81 ◽  
Author(s):  
Jing Guo ◽  
Julie A. Lovegrove ◽  
David I. Givens
Keyword(s):  
Vitamin D ◽  
Ethnic Minority ◽  
Ultraviolet B ◽  
Dietary Vitamin ◽  
Minority Populations ◽  
Vitamin D Status ◽  
Vitamin D Intake ◽  
Ethnic Minority Populations ◽  
Dietary Vitamin D ◽  
Lower Vitamin

In recent years, vitamin D deficiency has attracted attention worldwide. Especially many ethnic minority populations are considered at high-risk of vitamin D deficiency, owing to a lesser ability to synthesis vitamin D from sunlight (ultraviolet B), due to the skin pigment melanin and/or reduced skin exposure due to coverage required by religious and cultural restrictions. Therefore, vitamin D intake from dietary sources has become increasingly important for many ethnic minority populations to achieve adequate vitamin D status compared with the majority of the population. The aim of the study was critically evaluate the vitamin D intake and vitamin D status of the ethnic minority populations with darker skin, and also vitamin D absorption from supplements and ultraviolet B. Pubmed, Embaase and Scopus were searched for articles published up to October 2018. The available evidence showed ethnic minority populations generally have a lower vitamin D status than the majority populations. The main contributory food sources for dietary vitamin D intake were different for ethnic minority populations and majority populations, due to vary dietary patterns. Future strategies to increase dietary vitamin D intake by food fortification or biofortification needs to be explored, not only for the majority population but more specifically for ethnic minority populations who are generally of lower vitamin D status.

scholarly journals Effect of smoking on the serum levels of 25-hydroxyvitamin D depends on the assay employed

2010 ◽  
Vol 163 (6) ◽  
pp. 965 ◽  
Author(s):  
Guri Grimnes ◽  
Bjørg Almaas ◽  
Anne Elise Eggen ◽  
Nina Emaus ◽  
Yngve Figenschau ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Serum Levels ◽  
Ultraviolet B ◽  
Vitamin D2 ◽  
Related Article ◽  
Hydroxyvitamin D ◽  
Article Type ◽  
25 Hydroxyvitamin D ◽  
Uvb Exposure

The authors and the journal apologise for errors in the Introduction section of this paper published in the European Journal of Endocrinology 2010 vol 163 pp 339–348. Lines 11–14 of the Introduction section should read as follows:This reflects the amount of vitamin D ingested from food (ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3)) and the amount of vitamin D produced in the skin during ultraviolet B (UVB) exposure (vitamin D3)and not as published.

scholarly journals Super-doses of dietary vitamin D3 intake in aged laying hens illustrates limitation of 24,25-dihydroxycholecalciferol conversion

2021 ◽  
Author(s):  
Matthew F. Warren ◽  
Pete M. Pitman ◽  
Dellila D. Hodgson ◽  
Kimberly A. Livingston
Keyword(s):  
Vitamin D ◽  
Vitamin D3 ◽  
Laying Hens ◽  
Dietary Vitamin ◽  
Plasma Vitamin ◽  
Vitamin D Metabolites ◽  
Vitamin D Status ◽  
Blood Calcium ◽  
Reduce Risk ◽  
Dietary Vitamin D

Background: Humans take vitamin D supplements to reduce risk of vitamin D deficiency and reduce the risk of osteoporosis. However, it is unclear how dietary super-dose (10,000x greater than requirement) can affect vitamin D status in aged animals. Aged laying hens could potentially be a model to compare with women in peri- or postmenopausal stages of life because their bone health is physiologically taxed from egg production and they are highly susceptible to osteoporosis. Objective: We investigated dietary super-dose impacts of cholecalciferol (vitamin D3) on vitamin D status in aged laying hens in production. Methods: Forty-eight 68-wk old Hy-Line Brown laying hens were individually housed in cages with eight hens per dietary treatment for eleven weeks. Hens were randomly assigned to one of six groups of dietary vitamin D3 supplementation and fed ad libitum. Supplementation levels were 400 (recommended dosage for hens), 800, 7,400, 14,000, 20,000, and 36,000 IU D3/kg of feed. At termination of the study, all hens were euthanized and we collected blood, feces, and tibia and humerus bones. Ionized (free) blood calcium, fecal calcium, bone calcium, and plasma vitamin D metabolites were measured. Results: We did not discern any dietary effects in tissue and fecal calcium. We observed that increasing dietary vitamin D3 increased plasma vitamin D3, 25-hydroxycholecalciferol, and 24,25-dihydroxycholecalciferol concentrations (p < 0.0001 for all 3 metabolites). We also observed super-dose fed hens had decreased kidney 24-hydroxylase expression (p = 0.0006). Conclusions: Although dietary vitamin D3 super-doses did not affect calcium status in our aged laying hens, it is possible there is an age-related effect of not being as sensitive to vitamin D efficacy. We suggest future research should explore how 24-hydroxylation mechanisms are affected by vitamin D supplementation. Further understanding of 24-hydroxylation can help ascertain ways to reduce risk of vitamin D toxicity.

scholarly journals Prevalence and Predictors of Vitamin D Deficiency among African Immigrants Living in Australia

2019 ◽  
Vol 16 (16) ◽  
pp. 2855 ◽  
Author(s):  
Kahlea Horton-French ◽  
Eleanor Dunlop ◽  
Robyn M. Lucas ◽  
Gavin Pereira ◽  
Lucinda J. Black
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
African Immigrants ◽  
Sun Exposure ◽  
Prevalence Ratio ◽  
Ultraviolet B ◽  
Dietary Vitamin ◽  
Public Health Issue ◽  
Activity Levels ◽  
Australian Health

Vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) concentrations <50 nmol/L) is a public health issue in Australia and internationally. Those with darker skin require a greater dose of ultraviolet B radiation from sunlight than those with paler skin to synthesise adequate amounts of vitamin D. Using data from the 2011–2013 Australian Health Survey, we investigated the prevalence and predictors of vitamin D deficiency in African immigrants aged ≥18 years living in Australia (n = 236). Serum 25(OH)D was measured using a liquid chromatography–tandem mass spectrometry method that is certified to international reference measurement procedures. Poisson regression was used to investigate independent predictors of vitamin D deficiency. A total of 36% of adults were vitamin D deficient (35% of men, 37% of women). The prevalence ratio (PR) of vitamin D deficiency decreased by 2% per year of age (PR 0.98; 95% CI (0.97, 0.99); p = 0.004) and was 1.6 times higher in those with low/sedentary, compared to moderate/high, physical activity levels (PR 1.64; 95% CI (1.12, 2.39); p = 0.011). The greatest risk was for those assessed during winter/spring compared with summer/autumn (PR 1.89; 95% CI (1.33, 2.64); p < 0.001). Culturally appropriate messaging on safe sun exposure and dietary vitamin D is warranted in order to promote vitamin D sufficiency in African immigrants living in Australia.

Sources of vitamin D for humans

2021 ◽  
Author(s):  
Evgen Benedik
Keyword(s):  
Vitamin D ◽  
Dietary Supplements ◽  
Current Knowledge ◽  
Vitamin D Insufficiency ◽  
Ultraviolet B ◽  
Dietary Vitamin ◽  
Fortified Foods ◽  
Fortified Food ◽  
25 Hydroxy Vitamin D ◽  
Different Sources

Abstract. Both vitamin D insufficiency and deficiency are now well-documented worldwide in relation to human health, and this has raised interest in vitamin D research. The aim of this article is therefore to review the literature on sources of vitamin D. It can be endogenously synthesised under ultraviolet B radiation in the skin, or ingested through dietary supplements and dietary sources, which include food of animal and plant origin, as well as fortified foods. Vitamin D is mainly found in two forms, D3 (cholecalciferol) and D2 (ergocalciferol). In addition to the D3 and D2 forms of vitamin D, 25-hydroxy vitamin D also contributes significantly to dietary vitamin D intake. It is found in many animal-derived products. Fortified food can contain D3 or D2 forms or vitamin D metabolite 25-hydroxy vitamin D. Not many foods are a rich source (> 4 μg/100 g) of vitamin D (D represents D3 and/or D2), e.g., many but not all fish (5–25 μg/100 g), mushrooms (21.1–58.7 μg/100 g), Reindeer lichen (87 μg/100 g) and fish liver oils (250 μg/100 g). Other dietary sources are cheese, beef liver and eggs (1.3–2.9 μg/100 g), dark chocolate (4 μg/100 g), as well as fortified foods (milk, yoghurt, fat spreads, orange juice, breakfast grains, plant-based beverages). Since an adequate intake of vitamin D (15 μg/day set by the European Food Safety Authority) is hard to achieve through diet alone, dietary supplements of vitamin D are usually recommended. This review summarizes current knowledge about different sources of vitamin D for humans.

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