Vitamin D is essential for:
- Bones and teeth
- The immune system
- Brain health
- Regulation of inflammation
The body produces vitamin D in response to sun exposure, and certain foods and supplements can also increase your intake of vitamin D. Despite its name, vitamin D is not a vitamin, but a hormone or prohormone.
The role of vitamin D in the body
Healthy bones
- Vitamin D promotes calcium absorption and helps maintain proper levels of calcium and phosphorus in the blood, which are necessary for healthy bones and teeth.
- Vitamin D deficiency in children can cause rickets, leading to softening of the bones and dental problems.
- In adults, vitamin D deficiency can manifest as osteomalacia (softening of the bones) and long-term deficiency can lead to osteoporosis (low bone density), increasing the risk of fractures.
Immune function
Adequate vitamin D intake can support good immune function and reduce the risk of autoimmune diseases. Researchers believe there may be a link between long-term vitamin D deficiency and the development of autoimmune conditions, such as type 1 diabetes and rheumatoid arthritis, but more research is needed to confirm the link.
Vitamin D deficiency
- Lack of sun exposure: Northern climate, high pollution, night shifts.
- Skin color: Darker tones synthesize less vitamin D.
- Age: The ability to synthesize decreases with age.
- Breastfeeding: Breastfed babies need supplements.
- Body weight: Excess fat limits absorption.
- Medical conditions: Fat absorption problems.
- Gastric bypass surgery: It affects the absorption of vitamin D.
Symptoms of vitamin D deficiency
Most people with vitamin D deficiency have no symptoms. However, a chronic deficiency can cause osteomalacia, which can lead to:
- Bone pain
- Joint pain
- Weakness or muscle spasms
- Problems with bone or tooth development
Over time, weakened bones can contribute to osteoporosis and increase the risk of falls and fractures, especially in older adults. Vitamin D deficiency can also lead to hyperparathyroidism, which is when the parathyroid glands create a hormonal imbalance that raises blood calcium levels too much.
Vitamin D in babies and children
- Important for bone development.
- Deficiency causes rickets and is linked to high blood pressure and allergies.
Vitamin D in pregnancy
- Deficiency can increase the risk of preeclampsia and premature births.
- Possible association with gestational diabetes and the development of allergies in newborns.
Sources of vitamin D
- Fatty fish (salmon, mackerel, tuna)
- Egg yolks, cheese, beef liver, mushrooms
- Fortified milk, fortified cereals and juices
Recommended daily dose
- Infants 0-12 months: 400 IU
- Children 1-18 years: 600 IU
- Adults up to 70 years: 600 IU
- Adults over 70: 800 IU
- Pregnant or lactating women: 600 IU
The dangers of vitamin D
- Upper limit: 4000 IU per day for adults.
- Toxicity can cause hypercalcemia, fatigue, weakness, bone pain, nausea, and other serious symptoms.
People taking supplements should choose brands carefully as the FDA does not monitor the safety of supplements in the same way as pharmaceuticals.
