As people become more health-conscious, many are turning their attention to supplementing various nutrients. On the web, some claim they don’t get enough sun exposure or have low bone density, hence the need for extra vitamin D. However, others worry that too much vitamin D supplementation could harm the liver.
In reality, both excess and deficiency of vitamin D are undesirable.
So, what are the benefits of vitamin D for the body? Who needs to supplement, and how should it be done scientifically?
First, let’s clarify the role of vitamin D. Vitamin D, a fat-soluble vitamin, plays a crucial role in bone health. Its endocrine system regulates blood calcium levels, maintaining the body’s normal calcium concentration.
Vitamin D also participates in regulating various bodily functions. It acts as a hormone, regulating growth, development, cell differentiation, immunity, and inflammatory responses through vitamin D receptors.
What about vitamin D deficiency?
Studies show a severe global vitamin D deficiency rate of 15.7% and an insufficiency rate of 44.7%.
For most people, vitamin D deficiency affects bone mineralization, resulting in abnormalities in bones and teeth.
For infants:
If deficient in vitamin D, they’re not only prone to rickets but may also develop softening and deformities of bones due to inadequate calcification, such as “X” or “O” shaped legs, chest protrusion, delayed closure of fontanelles, narrowed pelvis, and spinal curvature. Additionally, vitamin D deficiency often leads to poor development of abdominal muscles, causing abdominal protrusion. In terms of teeth, delayed eruption, dental caries, and sparse, concave permanent teeth are common.
For pregnant women:
Vitamin D deficiency can lead to osteomalacia, mainly manifested by softening and deformity of bones, pelvic deformation leading to difficult childbirth.
For older adults:
Vitamin D deficiency increases the risk of osteoporosis and subsequent fractures.
What happens with excessive vitamin D supplementation?
Excessive intake of vitamin D can cause various side effects, including loss of appetite, weight loss, nausea, vomiting, and soft tissue calcification and kidney stones, which can lead to death in severe cases.
So, how do we supplement vitamin D rationally?
Regular sun exposure is the most cost-effective way to effectively supplement vitamin D. Sunbathing for 10-20 minutes daily in the morning (9-10 am) or afternoon (4-5 pm) sunlight is sufficient. In terms of dietary supplementation, vitamin D is mainly found in animal foods such as fish liver (e.g., sardines), egg yolk, and fish oil supplements.
According to the recommendations of the National Institutes of Health (NIH) and the Food and Nutrition Board (FNB) in the United States, the recommended daily intake (RDA) varies for different age groups:
Infants (birth to 12 months): 400 international units (IU) of vitamin D per day.
Adults aged 1 to 70 years: 600 IU of vitamin D per day.
Adults aged 70 and older: 800 IU of vitamin D per day.
These recommended intake levels are to maintain the vitamin D levels necessary for bone health and other physiological functions.
However, individual requirements may vary depending on factors such as health status, lifestyle, and environmental factors. It is advisable to consult a doctor or nutritionist for advice if there are specific health conditions or the need for additional vitamin D supplementation.
References:
(1) Vitamin D | The Nutrition Source | Harvard T.H. Chan School of Public Health. https://www.hsph.harvard.edu/nutritionsource/vitamin-d/.
(2) Vitamin D Deficiency: MedlinePlus. https://medlineplus.gov/vitaminddeficiency.html.
(3) Vitamin D – Consumer – Office of Dietary Supplements (ODS). https://ods.od.nih.gov/factsheets/VitaminD-Consumer/.
(4) Vitamin D – Health Professional Fact Sheet – Office of Dietary Supplements (ODS). https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/.
(5) Vitamin D and your health: Breaking old rules, raising new hopes. https://www.health.harvard.edu/staying-healthy/vitamin-d-and-your-health-breaking-old-rules-raising-new-hopes.
(6) Taking too much vitamin D can cloud its benefits and create health risks – Harvard Health. https://www.health.harvard.edu/staying-healthy/taking-too-much-vitamin-d-can-cloud-its-benefits-and-create-health-risks.
(7) How much vitamin D do you need? – Harvard Health. https://www.health.harvard.edu/staying-healthy/how-much-vitamin-d-do-you-need.
Disclaimer:
The information in this article is for general information sharing purposes only. It is not a substitute for personalized medical or dietary advice. For personal health concerns and dietary needs, consult a qualified health care provider or dietitian.