Vitamin D— the sunshine vitamin is absolutely essential for good health.
Vitamin D is made in the skin when exposed to sunlight, and in spite of that, it is the most common nutrient deficiencies in the world.
Vitamin D is essential for bone health and immune system function. In children, vitamin D deficiency may lead to a condition known as rickets (a condition in which the bone tissue doesn’t properly mineralize, leading to skeletal deformities and soft bones).
Vitamin D is protecting against a host of health problems; some of the benefits include:
- Helping the body to absorb calcium for strong bones
- Playing a part in muscle movement
- Supporting nerves in signal transmission to and from the brain
- Supporting the immune system to fight infections and diseases
How Much to Get?
Guidelines on the amount of vitamin D intake are always unclear. Some people will be able to get enough vitamin D from sunlight alone; however, others need to make changes to lifestyle or take supplements.
Recommended daily intake of vitamin D depending on the age is as follows:
- Infants from 0 to 12 months: 400 IU
- For age group from 1 to 70 years: 600 IU
- For the age group 70 years and above: 800 IU
The safe upper limit for vitamin D is 4,000 IU. Doctors may prescribe more than 4,000 IU to correct a vitamin D deficiency.
You can get vitamin D from:
- Sun exposure
- Foods that contain vitamin D
Very few foods are known to contain significant amounts of vitamin D leading to the low intake of it.
Foods that contain vitamin D include fatty fish like salmon, as well as fish liver oils. Egg yolks also contain small amounts of it, and milk and cereals are also enriched with vitamin D.
Supplements are also widely available and are safe and effective.
Understanding the Results
The most accurate way to measure the vitamin D levels in the body is with a blood test known as 25-hydroxy vitamin D.
A level of 20- 50 ng/mL is considered adequate for healthy people.
A level < 12 ng/mL indicates vitamin D deficiency.
However, levels below 20 ng/mL are too low for healthy bones and general wellbeing.
Bone pain and muscle weakness are common with vitamin D deficiency. For many people, the symptoms are subtle.
Risks associated with low blood levels of vitamin D include:
- Increased risk of death from cardiovascular disease
- Cognitive impairment in older adults
- Severe asthma in children
- Glucose intolerance
- Multiple sclerosis
Causes of Vitamin D Deficiency
Vitamin D deficiency can occur for several reasons:
Low intake of the vitamin over time: This is most common among those who follow a strict vegan diet because most of the natural sources are animal-based.
Limited exposure to sunlight: Body makes vitamin D when the skin is exposed to sunlight. Limited exposure in people who are homebound, live in northern latitudes, wear long robes, or have an occupation that prevents sun exposure are at risk of deficiency.
Dark skin: Dark skin is rich in pigment melanin. This pigment reduces the skin’s ability to make vitamin D in response to sunlight exposure.
Failure of kidneys to convert vitamin D to its active form: Ageing can affect kidneys by limiting their ability to convert vitamin D to its active form, thereby increasing the risk of vitamin D deficiency.
Problem with the absorption of vitamin D: People with some medical issues like Crohn’s disease, cystic fibrosis, and celiac disease, can affect the intestine’s ability to absorb vitamin D from the food.
Obesity: People with a BMI ≥ 30 often have low blood levels of vitamin D as the vitamin is extracted from the blood by fat cells, altering its release into the circulation.
Treatment for vitamin D deficiency is through diet and supplements.