Impact of melanin on vitamin D production and synthesis The amount of melanin in the skin affects vitamin D status because the skin depends on UV rays to synthesize vitamin D, and darker skin inhibits its production.
Melanin protects skin from the sun's ultraviolet rays. These can burn the skin and reduce its elasticity, leading to premature aging. People tan because sunlight causes the skin to produce more melanin and darken. The tan fades when new cells move to the surface and the tanned cells are sloughed off.
Vitamin D is a group of fat-soluble secosteroids that are responsible for several important biological processes, including our skin health. In fact, several causes of skin pigmentation can be traced back to vitamin-D deficiency.
Therefore, dark-skinned individuals will experience slower vitamin D synthesis than light-skinned ones. This is especially important at higher latitudes where the incidence and duration of sunlight is reduced.
Meanwhile, for the synthesis of vitamin D, we need to be exposed to sunlight. Hence, sun avoidance may result in decreased melanin levels and also low vitamin D levels. This can explain, at least partially, the positive correlation between melanin and vitamin D levels. This is supported by a study by Glass et al.
Because vitamin D is fat soluble, its absorption depends on the gut's ability to absorb dietary fat [4]. Fat malabsorption is associated with medical conditions that include some forms of liver disease, cystic fibrosis, celiac disease, Crohn's disease, and ulcerative colitis [1,63].
Safety and side effects
However, taking too much vitamin D in the form of supplements can be harmful. Children age 9 years and older, adults, and pregnant and breastfeeding women who take more than 4,000 IU a day of vitamin D might experience: Nausea and vomiting. Poor appetite and weight loss.
More specifically, about 50% of Asians, 33% of Black individuals, and 12% of Whites were vitamin D deficient. The body's ability to produce vitamin D appears to decline with age; therefore, higher vitamin D dosages are required for older people.
Until recently, the answer to this has been no. It was thought that once a hair follicle stopped making melanin, it wasn't possible for it to regain its color on its own. But a recent study showed that it may be possible to reverse gray hair — even if just temporarily.
Microscopic appearance. Melanin is brown, non-refractile, and finely granular with individual granules having a diameter of less than 800 nanometers. This differentiates melanin from common blood breakdown pigments, which are larger, chunky, and refractile, and range in color from green to yellow or red-brown.
However, the best way to support melanin production and good skin health is to eat a healthy diet full of vegetables, fruit, and whole grains. This eating style can reduce inflammation and provide sufficient vitamins and minerals for melanin production.
Conclusions. Sunscreen use for daily and recreational photoprotection does not compromise vitamin D synthesis, even when applied under optimal conditions.
Vitamin C is a naturally occurring substance and an essential nutrient. It has various biological and pharmaceutical functions. It inhibits melanin synthesis through downregulation of tyrosinase enzyme activity.
Results: Blacks had lower total 25(OH)D concentrations than whites [adjusted median: 20.3 ng/mL (95% CI: 16.2, 24.5 ng/mL) compared with 26.7 ng/mL (95% CI: 25.2, 28.1 ng/mL), respectively; P = 0.026)], and a higher proportion of blacks had total 25(OH)D concentrations <20 ng/mL (46% compared with 19%, respectively; P ...
For most adults, vitamin D deficiency is not a concern. However, some groups — particularly people who are obese, who have dark skin and who are older than age 65 — may have lower levels of vitamin D due to their diets, little sun exposure or other factors.
The pigment that makes human skin dark is called melanin. It helps protect you from ultraviolet B (UVB) light, but it can also block your skin's ability to make vitamin D after sunlight exposure.
In addition, taking a supplement that contains too much vitamin D can be toxic in rare cases. It can lead to hypercalcemia, a condition in which too much calcium builds up in the blood, potentially forming deposits in the arteries or soft tissues. It may also predispose people to painful kidney stones.
Iron and vitamin D – taking vitamin D can potentially decrease your iron levels. Take them at different times, morning and evening, for best efficacy. Vitamin E and vitamin K, fish oils/omega-3 – as these vitamins may impact blood vessel health in those on certain medications.
Research also demonstrated that the higher the level of caffeine, the more it interfered with vitamin D absorption. The study suggested that caffeine did this by reducing the expression of vitamin D receptors on osteoblasts in the body – the cells responsible for producing bone.
Magnesium plays an important role in liver and kidney function, and it's essential for the absorption of vitamin D. The enzymes that are responsible for metabolizing vitamin D all seem to require magnesium. 1 If your magnesium level is too low, your body cannot activate or process vitamin D.