Vitamin D

Vitamin D is well known for its importance and essential role in bone health, but it also has other significant roles in physical and mental health as well, and its deficiency might lead to serious health complications.

Vitamin D (calciferol)

Vitamin D is one of the fat-soluble vitamins, which means that it needs a fat-rich environment to be completely absorbed.

Vitamin D sources:

• Ultraviolet (UV) rays from sunlight: This is the main source of vitamin D. These rays trigger its synthesis internally by converting it from an inactive to an active form, which is called vitamin D₃. This process is impacted by several factors, such as the season, the time of day, if there are clouds or smog, skin color, and sun protection. In general, it’s recommended to have direct exposure to the sunlight for 5-30 minutes daily or twice a week at least between 10 am and 4 pm without any sun protection.
• Despite the fact that sunlight is the main source of vitamin D, we must pay attention to the fact that excessive exposure to UV rays is the most causative factor of skin cancer. Therefore, we mustn’t expose ourselves to sunlight for long periods without appropriate protection.
• Food: Fatty fish (such as tuna, salmon, mackerel, and sardines), in addition to fish liver oils, are the best sources of vitamin D. Vitamin D can also be found in egg yolks, beef liver, and cheese in small amounts, and also in chicken breast and certain mushroom types in smaller amounts.
• Nutritional supplements.

The risk of vitamin D deficiency increases in:

• Infants who are only breastfed.
• The elderly.
• People who don’t expose themselves enough to sunlight.
• Dark-skinned people.
• Low-vitamin D or low-fat diets.
• People with excessive obesity.
• People who have undergone gastric bypass surgery.
• Having certain drugs, such as orlistat (prevents fat absorption from food), statins (decrease cholesterol synthesis), and corticosteroids (cause impairment in the vitamin D metabolism and decrease calcium absorption).

The recommended intake of vitamin D:

• 400 IU daily for infants (from delivery until 1 year).
• 600 IU daily from the age of 1 until the age of 70 years old, in addition to pregnant and breastfeeding women.
• 800 IU daily for people older than 70 years old.

The importance of vitamin D (calciferol)

• A vital factor for calcium absorption, so it’s essential for bone health and preventing osteoporosis.
• It contributes to slowing down the development of tumor cells.
• It contributes to regulating blood pressure and reducing the risk of cardiovascular disease (CVD).
• The studies noticed that vitamin D deficiency is correlated with certain health conditions, such as tuberculosis (TB), type 2 diabetes, asthma, multiple sclerosis (MS), eczema, and obesity and overweight, in addition to depression.
• Severe vitamin D deficiency in infants or children causes rickets, and in adults, it causes osteomalacia, osteoporosis, and increased fractures.

Excessive vitamin D (calciferol)

• Excessive vitamin D, like its deficiency, also causes health problems, and vitamin D intoxication only occurs from unregulated intake of its supplements and not from excessive exposure to sunlight.
• Excessive vitamin D causes hypercalcemia, which causes neuropsychiatric disturbances, nausea and vomiting, muscle weakness, pain, loss of appetite, extreme thirst, polyuria, dehydration, and kidney stones. Hypercalcemia might also occur due to the intake of thiazide diuretics because they decrease the calcium excretion through the urine.
• In severe cases, vitamin D intoxication causes renal failure, calcification in the soft tissue (like coronary vessels and heart valves), cardiac arrhythmias, and death in some cases.

Therefore, it’s critical to not take vitamin D supplements spontaneously before consulting a healthcare provider.