How to supplement vitamin D scientifically and correctly?
1. Why should the human body need a supplement of vitamin D?
As a fat-soluble vitamin, vitamin D has a variety of physiological functions in the body.
(1). Skeletal actions of vitamin D:
Promotes intestinal absorption of calcium and phosphorus.
Inhibits the release of PTH.
Prevents calcium loss in the renal tubules.
Promotes calcium deposition.
Promotes bone remodeling.
Enhances skeletal muscle function.
(2). Vitamin D and DM (diabetes mellitus):
Helps prevent type 1 diabetes.
Affects the synthesis and secretion of insulin in type 2 diabetic patients.
Inhibits insulin inflammatory response and protects pancreas islet β cells.
Activates L-type calcium channels on β cells.
Enhances pancreas islet β cells, releases insulin to the greatest extent under the action of calcium ions.
Reduces insulin resistance.
Reduces the incidence of complications such as diabetic osteoporosis and cardiovascular disease.
(3). Non-skeletal actions of vitamin D:
Cardiovascular effects: serum vitamin D levels are negatively correlated with hypertension and vitamin D can enhance myocardial contractility.
Effects on the nervous system: vitamin D prevents neuronal loss and vitamin D receptors are associated with neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, depression, etc.
Guarantees the development of the fetus during pregnancy.
2. Grading of vitamin D levels.
At present, a serum vitamin D level reaching 50-250 nmol/L (20-100 ng/mL) is considered as an appropriate vitamin D nutritional status.
The relatively accepted grading criteria are those established by the American Endocrine Society:
>75nmol/L(30ng/mL) is adequate.
50-75 nmol/L(20-30ng/mL) is not enough.
<50 nmol/L (20ng/mL) is deficient.
<10ng/mL is severely inadequate.
3. Is vitamin D supplementation equivalent to calcium supplementation?
Vitamin D is a kind of vitamin. Vitamin D and calcium are two completely different nutrients. Vitamin D can promote the absorption of calcium. However, if vitamin D is not supplemented, even if it is supplemented with more calcium, the utilization of calcium is very limited.
4. Is vitamin D the same as fish liver oil and vitamin AD?
Fish liver oil: mainly extracted from deep-sea fish, the main components include vitamin A, vitamin D and other jade components.
Vitamin AD: mainly synthetic, its main components are vitamin A, vitamin D.
Vitamin D: mainly synthetic, its main component is vitamin D.
Given the high risk of vitamin A deficiency in the Chinese population, vitamin A supplementation is also recommended. The ratio of general vitamin D and vitamin A supplementation is 1 to 3. Most fish liver oil and vitamin AD drops on the market in China are within the safe range.
5. Where does vitamin D come from?
Skin absorbs sunlight to synthesize vitamin D;
Fish liver oil;
Fatty fish (herring, salmon, tuna, sardines, sawfish, eel, catfish, etc.);
Animal Liver (chicken liver, duck liver, pork liver, bovine liver, etc.);
Whole milk (skim milk has little vitamin D and fortified AD milk has the highest vitamin D).
6. What are the factors affecting vitamin D synthesis?
Skin exposure time to sunlight;
Use of sunscreen.
7. How do you determine how much vitamin D should be supplemented?
According to China's new version of relevant recommendations for vitamin D supplementation, the preventive dose of vitamin D is 400-800IU/day (1IU=10ug) and 400 IU/day or 800IU/day can be selected according to different conditions such as North China or South China, winter or summer.
Premature infants, low birth weight infants and twins should start with a supplement of vitamin D of 800-1000IU/day after birth and change to 400-800IU/day after three consecutive months.
The recommended vitamin D supplement dose for women in late pregnancy is 800-1000IU/day.
Vitamin D supplementation starts from the perinatal period, focusing on infants and young children and continues until adolescence.