About Vitamin D
Popularly known as ”The sun vitamin”, was discovered around 100 years ago (1922-1925) (Wolf, 2004). It is a fat-soluble vitamin (hydrophobic in nature) primarily known for its role in optimizing bone health.
The food only contains around 05-20% of the total Vitamin D required by the human body. The body can synthesize most of it itself in the skin in the presence of sunlight.
Sources of vitamin D
In the 21 st century, due to the lifestyle, humans do not receive enough sun exposure. As a result, the deficiency of vitamin D is very common.
Some food sources have vitamin D naturally, and others are fortified with it. Common sources include salmon, canned tuna, cod liver oil, egg yolk, shrimp, mushrooms, fortified milk, and fortified cereals.
Vitamin D can also be synthesized by the skin in the presence of sunlight.
Deficiency status
Adequate exposure to sunlight and consumption of dietary sources of vitamin D are generally sufficient to avoid a deficiency. However, variables like the color of your skin and clothes may impact the absorption of Vitamin D from sunlight.
Rickets is one type of vitamin D deficiency. The physical symptoms in infants and children include bow-shaped legs, knock knees, and abnormal curvature of the spine.
In adults, the deficiency results in impaired calcium status. This condition manifests itself as bone pain and Osteomalacia ( A condition in adults with weak and softened bones that can be reversed with supplementation. This is different than osteoporosis, in which the bones get brittle and the condition is irreversible ). The evidence suggests that deficiency of this micronutrient may have importance around heart disease, weakened immune system (Martens et al., 2020), arthritis, depression, and obesity (Mitri and Pittas, 2014).
The population who has higher chances of getting deficiency includes:
- People with any conditions that affect the normal digestion of fats.
- People who don’t get enough vitamin D from sunlight as well as food.
- People with darker skin color. Melanin, a pigment present in the skin, in higher amounts, interferes with the production of Vitamin D.
- People who have undergone gastric bypass surgery, which typically removes the upper part of the small intestine where vitamin D is absorbed.
How to fight deficiency?
Before taking any supplement, consulting a doctor is extremely necessary. Excess vitamin D is stored in fat tissues. If too much vitamin D accumulates in fat tissues, it can lead to hypervitaminosis or, in the worst case, vitamin D poisoning. It can further escalate and can increase bone demineralization, which in turn, can weaken the bones and will increase calcium levels in the blood as large amounts of calcium will be mobilized from the bones.
So, the question is, how much vitamin D should anyone take?
Listening to your doctor is the best thing a person can do to tackle any vital deficiencies.
So, if you’ve decided to go for a test and start taking supplements as prescribed, there are some protocols, which should be followed to get the most out of them.
Never take the oral supplements on an empty stomach, there should always be some fat in the diet, because vitamin D is fat-soluble and is best absorbed when it is dissolved in some fat in the intestines.
Not only fats, but you also need to make sure that there is enough calcium, magnesium, vitamin C, and vitamin K are coming from the diet/supplements. Magnesium and vitamin C are needed by the body to produce vitamin D, and vitamin K is involved in the incorporation of calcium into bones. And if there is not enough calcium when taking vitamin D, the vitamin D takes the calcium from the bone substance, which will increase bone demineralization.
Takeaway
Vitamin D is a fat-soluble vitamin, which is also a prohormone. Apart from the food sources, it can be produced by the body. The primary role of Vitamin D is to maintain the homeostasis of calcium, through different signaling pathways. Chances of deficiency can be reduced by adding small interventions in the lifestyle. Once the deficiency strikes, blood checks, a doctor’s prescription, and proper supplementation will help.
References
- Wolf, G. (2004). The discovery of vitamin D: the contribution of Adolf Windaus. The Journal of nutrition, 134(6), 1299-1302.
