What happens when vitamin D is too low?
Chloe Ramirez
Updated on March 11, 2026
Vitamin D deficiency
Vitamin D deficiency or hypovitaminosis D is defined as a vitamin D level that is below normal. It most commonly occurs in people when they have inadequate sunlight exposure (in particular sunlight with adequate ultraviolet B rays (UVB)).
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What are the symptoms of low vitamin D?
Vitamin D helps with strong bones and may help prevent some cancers. Symptoms of vitamin D deficiency can include muscle weakness, pain, fatigue and depression.
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Signs and symptoms might include:
- Fatigue.
- Bone pain.
- Muscle weakness, muscle aches, or muscle cramps.
- Mood changes, like depression.
Is vitamin D deficiency serious?
If left untreated over time, vitamin D deficiency can lead to serious bone disorders. For example, severe and long-term vitamin D deficiency may result in rickets or osteomalacia.Does low vitamin D cause weight gain?
A vitamin D deficiency is unlikely to cause weight gain. However, it may cause other health problems or unpleasant symptoms, which are worth avoiding. You can maintain adequate vitamin D levels through a combination of limited sun exposure, a vitamin-D-rich diet, and taking vitamin D supplements.Does vitamin D affect sleep?
Research links vitamin D levels to sleep quality. In fact, several studies associate low levels of vitamin D in your blood to a higher risk of sleep disturbances, poorer sleep quality and reduced sleep duration ( 9 , 10 , 11 ).Why would vitamin D be low?
(Rickets; Osteomalacia) Vitamin D deficiency is most commonly caused by a lack of exposure to sunlight. Some disorders can also cause the deficiency. The most common cause is lack of exposure to sunlight, usually when the diet is deficient in vitamin D, but certain disorders can also cause the deficiency.How can I raise my vitamin D levels quickly?
You can raise your vitamin D levels quickly in three main ways: Getting outside and exposing your skin to sunlight. Taking a vitamin D supplement.
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Eat foods rich in vitamin D
- Cod liver oil*
- Trout*
- Salmon*
- Mushrooms*
- Fortified dairy and non-dairy milks.
- Fortified cereals.
- Sardines.
- Eggs.
Which of the following illnesses can be caused by a lack of vitamin D?
Traditionally, vitamin D deficiency has been associated with rickets, a disease in which the bone tissue doesn't properly mineralize, leading to soft bones and skeletal deformities.How long does it take to recover from vitamin D deficiency?
“If you put people on 2,000-4,000 [milligrams] of vitamin D based on what their deficient value was, you can usually get them corrected in four to six weeks, which is when you are really going to need the vitamin D.Can lack of vitamin D cause anxiety?
Research indicates that there is a strong link between vitamin D deficiency and anxiety as well as depression. Individuals struggling with a mental illness may turn to problematic behavior to mask the pain.Can lack of vitamin D cause dizziness?
Vitamin D deficiencies can also result in bone diseases such as rickets in children and osteomalacia and osteoporosis in adults. But you may not be aware that if you're not getting enough vitamin D, you may also suffer from dizziness, headaches, and yes, low energy and fatigue.How can I check my vitamin D levels at home?
At-home tests typically have you prick and squeeze a finger to collect a smaller blood sample. It's easier to measure 25-OH D because it lasts longer in the bloodstream, around 14 days. It's also easier to detect changes in 25-OH D levels that are associated with vitamin D deficiency.How long does it take for vitamin D levels to return to normal?
If you've been prescribed high-dose vitamin D, work closely with your doctor to monitor your blood levels. It can take three months or more to bring them back up, but once they're good, you can stop the high doses and return to a lower vitamin D supplement for maintenance.Can lack of vitamin D cause leg pain?
A vitamin D deficiency can affect both physical and mental health, but many people have low levels of vitamin D without realizing. The physical symptoms of a deficiency may include muscle pain in the joints, including rheumatoid arthritis (RA) pain, which often occurs in the knees, legs, and hips.Can low vitamin D levels cause shortness of breath?
Also, they found that patients with vitamin D deficiency had significantly higher scores in the Modified Medical Research Council Dyspnea Scale, which indicates more severe shortness of breath, compared to those who were not vitamin D deficient.Can vitamin D affect mood?
Vitamin D may regulate mood and reduce depressionResearch has shown that vitamin D might play an important role in regulating mood and decreasing the risk of depression. A review of 7,534 people found that those experiencing negative emotions who received vitamin D supplements noticed an improvement in symptoms.