Your body sources vitamin D through sunlight exposure. Specifically, ultraviolet (UV) radiation helps your body to produce vitamin D in the skin. But with concerns about skin cancer risks - as well as increased sunscreen usage - more and more people aren’t getting enough vitamin D.
There are actually two different forms of vitamin D: Vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Both forms increase the level of vitamin D in your blood, but the most common form available as a supplement is vitamin D3.
Recent research suggests vitamin D may have other benefits, too - like protecting against colds and fighting depression.
Vitamin D health benefits
There is strong evidence associating vitamin D supplements with the following health benefits:
- Supports bone health
- Builds and maintains muscle strength
- Prevents and treat vitamin D deficiency
- Promotes absorption of calcium
- Supports healthy muscles
- Reduces the risk of falls
How does vitamin D prevent falls?
There is a strong body of evidence linking low vitamin D levels to an increased risk of falling. Vitamin D deficiency can lead to impaired muscle function and muscle weakness. It’s thought that this reduced muscle function, in connection with the bone-related effects of vitamin D deficiency, is what leads to an increased risk of falls among older people.
Studies have also shown that elderly people who have low levels of vitamin D experience more falls than those with an adequate vitamin D intake. Supplementing with vitamin D is associated with a 22% reduced risk of falling - and research has also indicated that high doses of vitamin D tend to work better than low doses.
Vitamin D deficiency has also been linked to weak quadriceps, slow reaction times, impaired postural stability and slow functional performance.
Vitamin D can help to:
- Reduce the risk of falls in the elderly
- Reduce the amount of falls in the elderly
How does vitamin D support healthy bones?
Vitamin D is essential for bone health because it helps your bones to absorb calcium. Vitamin D also plays a role in regulating calcium levels in the blood and supporting skeletal growth and maintenance. As you get older, your risk of osteoporosis increases dramatically. Your bones become frail and more fragile, and if you fall they can fracture easily.
If you don’t get enough vitamin D, you may have an increased risk of fractures from falls. Supplements containing vitamin D3 and calcium have reduced the risk of both fractures and bone loss in older people in scientific studies.
Vitamin D can help to:
- Reduce the risk of fractures and bone loss in older people
- Support growth and maintenance of the skeleton
- Regulate calcium levels in the blood
Who is at risk of vitamin D deficiency?
Vitamin D deficiency is thought to be widespread among the Western world - and it’s often known as ‘The silent epidemic of the elderly’. Elderly people are most at risk of deficiency: not only do they spend a lot of time indoors, but their ability to produce vitamin D through sunlight exposure wanes as they age. Deficiency isn’t just linked to the elderly, though. Researchers estimate that up to half of the general population could be at risk.
Specifically, you may be at risk of vitamin D deficiency if:
- You don’t get enough sunlight - if you spend a lot of time indoors, are covered up a lot or live in northern latitudes
- You don’t consume an adequate intake of vitamin D - vegans are particularly at risk as most sources of vitamin D are animal products
- You have a certain syndrome or condition that impacts your ability to absorb vitamin D (eg Crohn’s Disease, celiac disease, weight loss surgery)
- You have dark skin - research has linked dark skin with vitamin D deficiency in older adults, possibly because melanin reduces your ability to make vitamin D from sunlight exposure
A severe vitamin D deficiency can lead to the development of rickets, a disease in which bones fail to properly develop. Vitamin D deficiency can also cause osteomalacia (weak bones and muscles).
Vitamin D deficiency is also associated with the following health risks:
- Weak immune system
- Increased cancer risk
- Poor hair growth
- Cognitive impairment
- Childhood asthma
- Increased risk of dying from heart disease
Symptoms of vitamin D deficiency include:
- Bone pain
- Muscle weakness
In addition to preventing the health risks associated with vitamin D deficiency, research has also implicated the prevention and treatment of vitamin D deficiency in several different conditions, including:
- Type 1 diabetes
- Type 2 diabetes
- Glucose intolerance
- Multiple sclerosis
Who can benefit from taking a vitamin D supplement?
A vitamin D supplement may be recommended for you if you:
- Don’t get enough exposure to natural sunlight
- Have low blood levels of vitamin D
- Don’t consume enough vitamin D in your diet (ie vegans)
- Are at risk of developing osteoporosis
- Can’t absorb vitamin D from your digestive tract adequately
Does vitamin D have any side effects?
Side effects associated with vitamin D supplements are rare. Some reported side effects include weakness, headache, appetite loss, dry mouth, metallic taste, nausea, vomiting, fatigue, drowsiness, and others.
If you take vitamin D supplements for a long time, you may increase your risk of high blood calcium levels. If you’re considering taking a vitamin D supplement, talk to your health professional about your specific nutritional requirements.
Vitamin D supplement combinations
Vitamin D supplements are often combined with vitamin K2 for bone health. This is because these vitamins regulate the way calcium is being used in the body and help to transport calcium to the bones instead of forming plagues in the arteries. Vitamin D can also be combined with calcium to help support bone health.
Vitamin D medicine interactions
Vitamin D supplements may interact with other medications you may be taking, so you should always discuss your medications with your healthcare professional. Medicines that are known to interact with vitamin D include: aluminium, calcipotriene, Diltiazem, Verapamil, and certain diuretics.
Vitamin D contraindications and cautions
If you’re pregnant or breast-feeding, vitamin D supplements are considered safe when taken at the recommended dose. If you have kidney disease, vitamin D supplements may increase your risk of atherosclerosis (hardening of the arteries).
Vitamin D supplements should also be used cautiously if you have any of the following conditions: sarcoidosis, histoplasmosis, hyperparathyroidism, lymphoma, tuberculosis. Discuss your health concerns with your healthcare professional if you’re considering vitamin D supplementation.
How much vitamin D do you need?
Always read the product label to determine the vitamin D dosage that’s right for you. Also, it’s important to be aware that many supplements containing vitamin D also contain other vitamins and minerals - including calcium and vitamin K2.
People of different ages have different vitamin D requirements. The upper level for adults is thought to be 4,000 IU, but vitamin D can be harmful when consumed in high doses. So if you have any questions or concerns, speak to your healthcare professional before you start taking vitamin D supplements.
Foods highest in vitamin D
Small amounts of vitamin D can be found in fish such as salmon, mackerel, tuna, and sardines - as well as fish liver oils, in particular cod liver oil. Vitamin D is also present beef liver, cheese, and egg yolks. Certain foods, like cereals, milk and orange juice, are fortified with vitamin D.
Food can’t generally provide your body with an adequate amount of vitamin D, so many people rely on sun exposure as a source. But many of us don’t get enough sun exposure, either. What’s more, some people have trouble converting vitamin D. That’s why supplementation is often required for people who have low vitamin D levels.
Why take a vitamin D supplement?
Vitamin D supplements may be beneficial for you if you’re looking to:
- Prevent your risk of falls
- Reduce your risk of fractures from falls
- Support healthy bones and muscle
- Prevent your risk of osteoporosis
- Prevent and treat vitamin D deficiency
- Help promote absorption of calcium
Other names of vitamin D
Calcitriol, calcidiol, calciferol, ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), 1,25-D, the sunshine vitamin, 1,25 dihydroxycholecalciferol, 25 hydroxycholecalciferol, 1,25 dihydroxyvitamin D