Vitamin D
Vitamin D is a group of fat-soluble secosteroids. Also known as the sunshine vitamin. Despite having the vitamin name it is considered to be a prohormone and not a vitamin. The nutrients of the vitamin can either be obtained from food supplements. Its major source is from the sunlight.
The vitamin is made up of compounds vitamin D-1, vitamin D-2, and vitamin D-3.
Vitamin D requirements
In a rough estimate, sensible sun exposure on bare skin for 5-10 minutes 2-3 times per week allows one to produce sufficient vitamin D. However, vitamin D breaks down quickly thus it can be low in the winter. Infants up to the age of 1 year need 8.5 to 10 micrograms of the vitamin in a day.
Adults and children from the age of one year need 10 micrograms in a day. This includes both expectant, lactating women and also people at the risk of vitamin D deficiency.
Vitamin D Sources
The main source is the sun but there are also other supplements with low nutritional value. The richest food sources of vitamin D are fish oil and fatty fish. These food sources include:
- cod liver oil, 1 tablespoon: 1,360 IU
- herring, fresh, raw, 4 ounces: 1,056 IU
- swordfish, cooked, 4 ounces: 941 IU
- raw maitake mushrooms, 1 cup: 786 IU
- salmon, sockeye, cooked, 4 ounces: 596 IU
- sardines, canned, 4 ounces: 336 IU
- fortified skim milk, 1 cup: 120 IU
- tuna, canned in water, drained, 3 ounces: 68 IU
- egg, chicken, whole large: 44 IU
Another source of vitamin D is dietary supplements. If milk is not fortified then vitamin D is not present in the milk.
Vitamin D Health Benefits
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To fight diseases
This is by reducing your risk of multiple sclerosis. Vitamin D can either prevent the occurrence of MS or prevent frequency and severe symptoms. The vitamin supplements in MS affected people are safe until you overdose. Overdosing will lead to changes in calcium levels. Thus there is still more research to be done.
Decreasing the chances of developing heart disease- when one ails from Vitamin D deficiency then he/she might be prone to heart failure, and ischemic heart disease. Thus when one gets vitamin D, they are far from heart disease dangers. (This is according to findings in Circulation-2008)
Help reduce the likelihood to develop flu. This is by increasing the number of antimicrobial proteins that fight against the influenza virus. Also, Vitamin D will help reduce inflammation caused by the flu virus, influenza virus.
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To reduce depression
According to various researchers, Vitamin D will play an important role to regulate the mood and warding off depression.
Scientists found out that depressed people who take vitamin supplements had an improvement in their symptoms.
Also, it was found out that, vitamin D deficiency was common in depressed people.
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Boosting weight loss
When taking supplements of both vitamin E and calcium, you can reduce weight. Both of them have an appetite-suppressing effect.
In a study, people taking the two were fit than the ones taking a placebo supplement. Also, overweight people taking daily vitamin D supplements had improved heart disease risk markers.
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Cognitive impairment
This is when a person has trouble remembering, learning new things, concentrating or making decisions. It can range from mild to severe. The vitamin’s biological function has shown neuroprotective effects including the clearance of amyloid plaques.
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Asthma Pathogenesis
Decreased vitamin D levels increase the airway smooth muscle(ASM) and reduce lung function in severe asthma. Thus we require the vitamin to balance the equation
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Maintain skeletal calcium balance
Vitamin D does this by promoting calcium absorption in the intestines. Additionally, promoting bone resorption by increasing osteoclast number. This helps in bone remodeling On the other hand, the vitamin maintains calcium and phosphate levels for bone formation. Thus allowing proper functioning of parathyroid hormone to maintain serum calcium levels.
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Enzymatic reactions
Sometimes, vitamin D is used as a catalyst to express various enzymatic reactions. For example, it is required to express tyrosine hydroxylase, an enzyme for the amino acid catabolic reaction.
Vitamin D Deficiency
The deficiency is not common to most children in the developed world. However, it is common in elderly/ aged people. Continuity of the deficiency will lead to several diseases. These include:
Rickets
The disease is a result of calcium or phosphorus deficiency and also vitamin D deficiency. It is a requirement for the diffusion of calcium and phosphorus to form strong borns. Also, rickets can be caused by maternal vitamin D deficiency thus leading to a rickets infant affected birth.
Mainly it will affect the infants or children that are not exposed to the sun. This is because the lactating milk contains low levels of vitamin D. Rickets will tend to be at a high rate in countries where the sun is low. Fortified milk is an advisory to the children to prevent rickets.
Signs and Symptoms of rickets
- Soft and weak bones
- Impeded growth of deformed long bones
- Bending and bowing legs under their weight as children start to walk.
Osteoporosis
Osteoporosis is simply the condition where bones become weak and brittle. Also, the bones can be porous. As calcium will be absorbed in limited amounts in the absence of Vitamin D, then the bones will be weak. The disease increases the chances of breaking a bone.
Mainly the bones that break include the forearm, hip bone, and vertebrae in the spine. It is usually at the onset of old age.
Signs and Symptoms of Osteoporosis
- Fractures- until there is a bone fracture it will be the first sign
- Risk of falling
- Increased pain to the joints when performing daily duties.
- Chronic pain(long severe pain) on the affected areas
- One might develop a compressed back from compression of bones and fractures.
Osteomalacia
Osteomalacia is a disease where the bones soften due to imapired bone metabolism causing bone mineralization. It mainly affects adults with vitamin D deficiency patients at the highest risk.
The disease is similar to rickets it is only that it is referred to as Osteomalacia in adults.
Signs and Symptoms of Osteomalacia
- Diffuse joint and bone pain (especially of spine, pelvis, and legs)
- Muscle weakness
- Difficulty walking, often with a waddling gait
- Hypocalcemia (positive Chvostek sign)
- Compressed vertebrae and diminished stature
- Pelvic flattening
- Weak, soft bones
- Easy fracturing
- Bending of bones
Skin Pigmentation
Dark-skinned people living in temperate climates have been shown to have low vitamin D levels but the significance of this is not certain. They are less efficient at making it because the melanin in the skin hinders vitamin D synthesis
Vitamin D Side Effects
Taking too many vitamin D supplements over a long period can cause too much calcium to build up in the body (hypercalcemia). This can weaken the bones and damage the kidneys and the heart.
Absorbing the vitamin from the sun will not get you sick. However, if you’re out in the sun for long periods, you are at the risk of skin damage and skin cancer.
Excessive consumption of vitamin D (hypervitaminosis D) can lead to over calcification of bones and hardening of blood vessels, kidney, lungs, and heart. The most common symptoms of hypervitaminosis D are headache and nausea but can also include loss of appetite, dry mouth, a metallic taste, vomiting, constipation, and diarrhea.