What is vitamin D and what function does it have?
Vitamin D is a fat-soluble vitamin; in other words, it’s a type of vitamin that can be diluted in fat. The main function of vitamin D is to ensure the production of hormones, to strengthen the immune system and to improve bone and skin health.
Vitamin D can be synthesized by the human body. 80-90% of it, is produced by the action of ultraviolet rays on the skin. Only 10-20% of the total amount is covered by food intake. (2)
Getting the recommended amount of vitamin D into the body is essential to optimize metabolism. Lack of it can lead to nervous system diseases and symptoms of osteoporosis in older adults. Excess of it, which is known as hypervitaminosis can be fatal. (1)
Advised amount per day
The recommended amount of vitamin D ranges from 10 to 20 µg (micrograms) per day, depending on sex and age. This dose can be written as 400 IU – 800 IU. Adults over 70 years of age are advised to intake a larger amount.
Vitamin D can be accumulated in the body. Its excessive consumption can cause intoxication. The maximum daily dose is 1000 to 3000 IU for children and 4000 IU for adults. (2)
Table of the advised amount of vitamin D:
- Toddlers up to 12 months of age: 400 IU
- Children between 1 and 13 years of age: 600 IU
- Adolescents between 14 and 18 years of age: 600 IU
- Adults between 19 and 70 years of age: 600 IU
- Adults over 70 years of age: 800 IU
- Pregnant and breastfeeding women: 600 IU
Products that are high in vitamin D
There are two ways to cover the advised amount of vitamin D: through food and supplements. In addition, products increase their effectiveness when combined with ultraviolet light.
The simplest way to cover the advised amount per day is to increase the consumption of fatty fish, eggs and tuna. In addition, some brands of foods such as dairy products and cereals are fortified with this vitamin.
Foods
Most foods with vitamin D are animal-based. Fatty fish such as tuna, and liver are the ones with the highest content. Foods with vitamin D include:
- Sardine – 500 IU per 100 g
- Catfish – 440 IU per 100 g
- Beef liver – 350 per 100 g
- Salmon – 340 IU per 100 g
- Canned tuna – 235 IU per 100 g
- Chicken eggs – 20 IU every 60 g.
- Fungi – (Variable)
For those eating a vegetarian diet it’s advisable to include some supplemented food source. Foods fortified with vitamin D include:
- Milk
- Breakfast cereals
- Orange juice
- Other dairy products, such as yogurt
- Soy drinks
Lack of vitamin D – Symptoms and consequences
Chronic lack of vitamin D increases the risk of cardiovascular disease by 35% and some types of cancer by up to 14% (1).
A slight lack of vitamin D can lead to bone density loss, osteoporosis and fractures. Severe lack of vitamin D can lead to serious consequences such as rickets, a disease that causes bones to become soft and bend.
Studies link the lack of vitamin D to diabetes, high blood pressure and autoimmune diseases such as multiple sclerosis. There’s still more research to be done to confirm the effects of the lack of vitamin D on the body.
Hypervitaminosis D. What is it and what are its symptoms?
Too much of this vitamin can cause serious health outcomes. Hypervitaminosis can occur due to misuse of supplements, or in children due to poisoning as a consequence of accidentally eating cosmetics.
Hypervitaminosis D by food isn’t frequent. The most frequent cause is the combination of multivitamin supplements, fish oil and Omega-3 capsules with multiple vitamins. The symptoms of hypervitaminosis D are:
- Constipation
- High pressure
- Dehydration
- Fatigue
- Frequent urination
- Mood changes
- Irritability
- Muscular fatigue
- Vomiting
- Excessive thirst
- Anorexia
Vitamin D is one of the essential fat-soluble nutrients. Its main function is hormonal balance and maintaining healthy skin and bones. The recommended amount of vitamin D per day varies according to age. The usual is about 400-800 IU. It amounts to about 150 g of foods such as fatty fish and beef liver. Older adults are advised to intake a larger amount. Lack or excess of it can cause serious symptoms in the body.
Link: https://nutricion360.es/alimentos/vitaminas-y-minerales/vitamina-d-alimentos-funcion-hipervitaminosis-d
Date: December 30th, 2019
REFERENCES:
- VITAMIN D. https://www.researchgate.net/publication/263426096_VITAMINA_D
- Vitamin D: visión desde el laboratorio. http://www.endocrinologiapediatrica.org/revistas/P1-E4/P1-E4-S83-A99.pdf
- Vitamin D – Centro de Información de Micronutrientes. https://lpi.oregonstate.edu/es/mic/vitaminas/vitamina-D
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