Foreword: Vitamin D – The Important “Carrier” of Calcium

Vitamin D plays many essential roles in the body, most notably in develop and strengthen bones. Although vitamin D deficiency has declined due to fortified dairy products, it is still a common problem, especially in the elderly. This article will help you understand the causes, how to recognize, treat, and safely prevent vitamin D deficiency.

What is vitamin D and why do our bodies need it?

Vitamin D is a fat-soluble vitamin that acts as a smart “transporter”:

• Helps absorb calcium and phosphorusfrom food in the intestine into the blood.
• Stabilize blood calcium levels, thereby promoting bone health.
  Additionally, vitamin D is also thought to benefit muscle function and the immune system, although more research is needed in these areas.

Where does our body get vitamin D?

There are two main sources of vitamin D:

1. Sunlight:Our skin can synthesize vitamin D when exposed to sunlight. However, this ability is affected by the season, time of day, age, skin color and health status. Important Note: Sun exposure is not recommended as a primary means of vitamin D supplementation due to the risk of skin cancer.
2. Food:Food sources rich in natural vitamin D include fatty fish (salmon, mackerel), cod liver oil and egg yolksIn many countries, industrial cow's milk is the most common source of supplementation. Cereals and some other products are also often fortified with vitamin D.

Why are we deficient in vitamin D?

There are three main groups of causes:

• Not getting enough through diet:Diets low in foods rich in vitamin D are common in infants (especially those who are exclusively breastfed), the elderly, and people who do not consume dairy products.
• Poor absorption:Some diseases such as Celiac, Crohn or gastric bypass surgery may reduce the ability to absorb vitamin D from the gut.
• Metabolic disorders:Diseases of liver or kidney Chronic use may interfere with the conversion of vitamin D into the active form the body can use.

Consequences of vitamin D deficiency

Severe vitamin D deficiency can lead to:

• Ricketsin children (soft and deformed bones).
• Osteomalaciain adults (soft bones, pain).

However, the more common condition is “subclinical deficiency” – lower than normal vitamin D levels that do not cause obvious symptoms. This condition can still lead to:

• Reduced bone density(osteoporosis).
• Increased risk of falls and fractures.

Therefore, detecting and treating vitamin D deficiency is very important for maintaining long-term bone and joint health.

How to know if you have vitamin D deficiency?

Blood test called 25-hydroxyvitamin D [25(OH)D] is the gold standard for diagnosis. However, there are differences between organizations in the threshold for defining deficiency:

• According to Institute of Medicine (National Academy of Medicine), level ≥20 ng/mL (50 nmol/L)is considered sufficient for most healthy people.
• Meanwhile, American Endocrine Associationand many other experts recommend the level above 30 ng/mL (75 nmol/L) is optimal for ensuring bone and overall body health.

Based on these recommendations, deficiency is usually identified when the concentration below 20 ng/mL and serious shortage when below 12 ng/mL (30 nmol/L)Your doctor will interpret the results based on your specific health condition.

Treatment of vitamin D deficiency: How to supplement properly?

• Vitamin selection:The two common forms are Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Vitamin D3 is often preferred. because it is more effective in raising blood vitamin D levels.
• Dosage:Treatment dose depends on the severity of deficiency and will be doctor's specific instructions. Typically, treatment involves an initial high dose for a few weeks to allow for rapid recovery, followed by a daily maintenance dose.
  • Reference example:Severely deficient people may need to take 50,000 IU/week for 8 weeks, then maintain 800–1,000 IU/day.
• Don't forget Calcium:When supplementing vitamin D, make sure to get enough calcium from your diet (milk, small fish with bones, tofu, green vegetables) or supplements.
• Monitor:Your doctor will recommend a blood test after about 3 months of treatment to evaluate the effectiveness and adjust the dose accordingly.
• Warning:Taking too much vitamin D can be toxic, leading to hypercalcemia or kidney stones. Follow the instructions and avoid taking more than one vitamin D supplement at the same time.

Deficiency Prevention – Easier Than You Think!

• For healthy adults:Additional 800 IU (20 mcg) vitamin D3 daily This is usually enough to maintain a stable level. This is the general recommended dose. Specific needs may be higher in some subjects (such as obese people, dark skin) and should be consulted with a doctor.
• For infants and young children:Additional recommendations 400 IU (10 mcg) vitamin D daily as early as a few days after birth. Vitamin D is often included in multivitamin drops for babies.
• Food:Increase foods rich in vitamin D such as salmon, tuna, egg yolks and formula.
• Absolutely not.Excessive sunbathing or using tanning beds to supplement vitamin D increases the risk of skin cancer.